The commandment of the fast on the tenth day of Tishrei: To fast on the tenth day of Tishrei, and this is called The Day of Atonements (Yom HaKippurim), as it is stated (Leviticus 23:27), “But on the tenth of the month, etc. you shall afflict your souls.” The explanation appears in Sifra, Acharei Mot, Chapter 7:3): “[This refers to] affliction that causes a diminishing of the soul. What is this? This is eating and drinking.” And so [too,] did they, may their memory be blessed, explain in the Gemara (Yoma 74b). And the tradition also came about it, that it is forbidden for washing, anointing, wearing shoes, and sexual relations. And the language of Sifra, Parashat Acharei Mot, Chapter 8:3 is “From where [do we know] that Yom Kippur is forbidden for washing, anointing, [wearing shoes] and sexual relations? [Hence] we learn to say (Leviticus 23:32), ‘A Shabbat of shabbaton’” — meaning that the doubling of Shabbat (rest) indicates resting from these things [as well as] resting from nourishment of the body.
It is from the roots of the commandment that it was from the kindnesses of God towards His creatures to establish one day to atone for their sins with repentance — and as I wrote at length in the Order of Acharei Mot (Sefer HaChinukh 185) in the commandment of the service for Yom Kippur. And we were therefore commanded to fast on this day; as food and drink and the rest of the sensual pleasures propel the physical matter towards desire and sin, and they cause people to negate the form of the wise soul from seeking truth — which is the service of God and His ethics [which are] good and sweet for anyone with knowledge. And it is not fitting to do [this] on the day of his coming to judgment in front of his Master; to come with a soul darkened and confused from the food and drink, with thoughts of the material which is in it. As we only judge a person according to his deeds of that time. Therefore it is good for him to strengthen his wise soul and to subdue the physical in front of it on this glorious day, so that [the soul] will be fitting and prepared to receive its atonement, and [that] the veil of desires not prevent it.
From the laws of the commandment is that which they, may their memory be blessed, said (Yoma 80a) that the measure of eating of fitting foods on Yom Kippur to be liable for it from Torah writ is a large kakotevet. And the reason that the measure of eating of Yom Kippur is differentiated from the measure of eating other prohibitions in the Torah — which are with a kazayit — is because the Torah forbade eating on that day with an expression of affliction. And it does not state, “you shall not eat,” about it, like it states with other prohibitions. And the Sages explained that they received [the tradition] from those that were before them: that with a kazayit, it is called eating; but affliction in a man is so long as he has not eaten a kakotevet — since the mind of a man is not set at ease with less.
And the measure of a kotevet (large date) is more than a grogeret (fig cake) and less than a kabeitsah (the size of a large egg) and also less than three (textual variant - two) [large] olives (zayit) — as three (textual variant - two) olives are a kabeitsah. The principle of the matter is that one who is an expert was already exacting and measured on a scale that there is not in the measure of twelve argents and more, the measure of a kakotevet; and [so] its law is like [that of] half a measure. And so [too,] that which they said (Yoma 73a, 80b) that the measure of drinking is the fill of a man’s cheek, which is a kabeitsah — as they have already measured that an egg fills the cheek of a man. And with less than this, there is no prohibition [the liability for which is with] excision. Rather its law is like [that of] half a measure. And therefore [in the case of] someone who is sick — even though there is no full danger with him — if he is very weak; it is fitting to feed him and give him drink little by little, less than the measure that we said. And we give a gap of [time] enough for the eating of a peras (half loaf of bread) — which is three eggs, according to the opinion of most commentators — between the eating and drinking of one time and [that of] another time, so that the eatings not combine and be considered one eating and [hence] one measure. But there is no need to pause between eating and drinking; as eating and drinking do not combine for this matter. And the measure between one drinking and [another] is [time] enough for the drinking of a reviit. And it is permitted to weigh and measure things on Yom Kippur at a time of need. And it is better that we be concerned and distance ourselves to not eat a measure and not be concerned to forbid measuring, which is [only] rabbinic. And also from the matter of the commandment is that which they, may their memory be blessed, said (Yoma 77b) [regarding] these afflictions that are only rabbinic — such as washing and anointing — they only decreed that they should not be done for no need. But they did not decree [about] anyone who does them for a need — for example, one who has scabs on his head [may] anoint them in his [customary] way and not be concerned. And they, may their memory be blessed (Yoma 77b), said that it is permitted to cross water until the neck even to guard fruits — and all the more so, for the matter of a commandment — whether going or returning.
And concerning the shoe (sandal), our teachers — God should protect them — explained that a shoe is always of leather. And that is what is forbidden on Yom Kippur, but not of a different type. And the principle of the matter according to some commentators is that anything that is fitting for the matter of release (chalitsah) — meaning to say, that it is of leather — is forbidden on Yom Kippur, and permitted to go out into a public domain with them (wearing them) on Shabbat. But anything that is not fitting for release — such as cork and reeds and palms (see Yoma 78b, that it is a shoe of grasses) and other types of grasses (plants) — are permitted on Yom Kippur, so long as they do not go out with them [to a public domain] in a place without an eruv, as we consider them like a burden (and not a piece of clothing, which is permitted). But from the commentators, there are [also] many honored ones that permit one to go out into the public domain with all of them.
And the law of the sick person who is in danger, that we feed him according to an expert physician, or according to himself — and even if the physician says that he does not need [to eat] (Yoma 83a); the law of a pregnant woman that smelled [food] (Yoma 82a, 83a); the law of one who was seized by bulimia; and the law of minors — whether a boy or a girl from what time do we we afflict them all of the day rabbinically, and likewise from when do we teach them [to fast] with [some] hours. And the principle of the matter according to a few of the commentators is that two years before the adulthood of a healthy child, they complete [the fast] rabbinically; and two years before that, we teach them [to fast] with [some] hours. And some explained that it is one year before adulthood that they complete [the fast] rabbinically — whether a boy or a girl. And some explained that only a girl alone completes [the fast] rabbinically one year before adulthood, but a boy does not complete [the fast] at all rabbinically. And adulthood for a boy is thirteen years and a day, and for a girl is twelve years and a day. And what is the law about washing for the king and the bride on this day (Yoma 73b).
And I will further mention to you here that which they, may their memory be blessed, said about the matter of the 9th of Av, which is well-known to be rabbinic. And even though these two days are very distant in their reasons and their content; since the word, “fast,” includes [both of] them, we will speak a little about it. And I will inform you that the Sages were stringent about it in all of its content like on Yom Kippur — to stop [eating] while it is still [the previous] day, and [about] anointing, wearing shoes and sexual relations. And pregnant and nursing women fast like the rest of the people - which they do not do on all other fasts, except for the middle three fasts of the stopping of rain. [This is] as it is mentioned in Tractate Taanit 14a at the end of the first chapter, where Rav Ashi concludes, “Take the middle [one] in your hand.” And the rest of the details of the commandment [of fasting on Yom Kippur] are elucidated in Tractate Yoma. (See Tur, Orach Chaim 612.)
And [it] is practiced in every place and at all times by males and females. And one who transgresses it and ate like the measure of a kotevet on Yom Kippur has violated a positive commandment, and has [also] transgressed a negative commandment that has [a liability of] excision for it; as it is stated (Leviticus 23:29), “For any soul which is not afflicted on that very day shall be excised.” [If] he ate or drank like this measure inadvertently, he is liable for a fixed sin-offering.
מִצְוַת תַּעֲנִית בְּיוֹם עֲשִׂירִי בְּתִשְׁרֵי – לָצוּם בְּיוֹם הָעֲשִׂירִי בְּתִשְׁרֵי, וְהוּא הַנִּקְרָא יוֹם הַכִּפּוּרִים, שֶׁנֶּאֱמַר (ויקרא כג כז) אַךְ בֶּעָשׂוֹר לַחֹדֶשׁ וְגוֹ' וְעִנִּיתֶם אֶת נַפְשׁוֹתֵיכֶם. וּבָא הַפֵּרוּשׁ בַּסִּפְרָא (אחרי מות ז ג) עִנּוּי שֶׁהוּא אִבּוּד נֶפֶשׁ, וְאֵיזֶהוּ? זֶה אֲכִילָה וּשְׁתִיָּה, וּכְמוֹ כֵן פֵּרְשׁוּהוּ זִכְרוֹנָם לִבְרָכָה בַּגְּמָרָא (יומא עד, ב). וְעוֹד בָּאָה הַקַּבָּלָה עָלָיו, שֶׁהוּא אָסוּר בִּרְחִיצָה, וּבְסִיכָה, וּבִנְעִילַת הַסַּנְדָּל, וּבְתַשְׁמִישׁ הַמִּטָּה, וּלְשׁוֹן סִפְרָא (שם ח ג) מִנַּיִן שֶׁיּוֹם הַכִּפּוּרִים אָסוּר בָּרְחִיצָה וּבְסִיכָה [וּבִנְעִילַת הַסַּנְדָּל] וּבְתַשְׁמִישׁ הַמִּטָּה? תַּלְמוּד לוֹמַר שַׁבַּת שַׁבָּתוֹן. כְּלוֹמַר, כִּי כֶּפֶל הַשְּׁבִיתָה, יוֹרֶה עַל שְׁבִיתָה מֵהָעֲסָקִים אֵלּוּ וּשְׁבִיתָה מִמְּזוֹן הַגּוּף.
The commandment of the fast on the tenth day of Tishrei: To fast on the tenth day of Tishrei, and this is called The Day of Atonements (Yom HaKippurim), as it is stated (Leviticus 23:27), “But on the tenth of the month, etc. you shall afflict your souls.” The explanation appears in Sifra, Acharei Mot, Chapter 7:3): “[This refers to] affliction that causes a diminishing of the soul. What is this? This is eating and drinking.” And so [too,] did they, may their memory be blessed, explain in the Gemara (Yoma 74b). And the tradition also came about it, that it is forbidden for washing, anointing, wearing shoes, and sexual relations. And the language of Sifra, Parashat Acharei Mot, Chapter 8:3 is “From where [do we know] that Yom Kippur is forbidden for washing, anointing, [wearing shoes] and sexual relations? [Hence] we learn to say (Leviticus 23:32), ‘A Shabbat of shabbaton’” — meaning that the doubling of Shabbat (rest) indicates resting from these things [as well as] resting from nourishment of the body.
מִשָּׁרְשֵׁי הַמִּצְוָה. שֶׁהָיָה מֵחַסְדֵי הַשֵּׁם עַל כָּל בְּרִיּוֹתָיו לִקְבֹּעַ לָהֶם יוֹם אֶחָד בְּשֵׁנָה לְכַפֵּר עַל הַחֲטָאִים עִם הַתְּשׁוּבָה, וּכְמוֹ שֶׁכָּתַבְתִּי בַּאֲרֻכָּה בְּסֵדֶר אַחֲרֵי מוֹת (מצוה קפה) בְּמִצְוַת עֲבוֹדַת יוֹם הַכִּפּוּרִים, וְלָכֵן נִצְטַוִּינוּ לְהִתְעַנּוֹת בּוֹ, לְפִי שֶׁהַמַּאֲכָל וְהַמִּשְׁתֶּה וְיֶתֶר הֲנָאוֹת חוּשׁ הַמִּשּׁוּשׁ, יְעוֹרְרוּ הַחֹמֶר לְהִמָּשֵׁךְ אַחַר הַתַּאֲוָה וְהַחֵטְא, וִיבַטְּלוּ צוּרַת הַנֶּפֶשׁ הַחֲכָמָה מֵחַפֵּשׁ אַחַר הָאֱמֶת שֶׁהוּא עֲבוֹדַת הָאֵל וּמוּסָרוֹ הַטּוֹב וְהַמָּתוֹק לְכָל בְּנֵי הַדַּעַת. וְאֵין רָאוּי לָעֶבֶד בְּיוֹם בּוֹאוֹ לַדִּין לִפְנֵי אֲדוֹנָיו לָבוֹא בְּנֶפֶשׁ חֲשׁוּכָה וּמְעֻרְבֶּבֶת מִתּוֹךְ הַמַּאֲכָל וְהַמִּשְׁתֶּה בְּמַחְשְׁבוֹת הַחֹמֶר אֲשֶׁר הִיא בְּתוֹכוֹ, שֶׁאֵין דָּנִין אֶת הָאָדָם אֶלָּא לְפִי מַעֲשָׂיו שֶׁבְּאוֹתָהּ שָׁעָה, עַל כֵּן טוֹב לוֹ לְהַגְבִּיר נַפְשׁוֹ הַחֲכָמָה וּלְהַכְנִיעַ הַחֹמֶר לְפָנֶיהָ בְּאוֹתוֹ הַיּוֹם הַנִּכְבָּד, לְמַעַן תִּהְיֶה רְאוּיָה וּנְכוֹנָה לְקַבֵּל כַּפָּרָתָהּ, וְלֹא יִמְנָעֶנָּה מָסַךְ הַתַּאֲווֹת.
It is from the roots of the commandment that it was from the kindnesses of God towards His creatures to establish one day to atone for their sins with repentance — and as I wrote at length in the Order of Acharei Mot (Sefer HaChinukh 185) in the commandment of the service for Yom Kippur. And we were therefore commanded to fast on this day; as food and drink and the rest of the sensual pleasures propel the physical matter towards desire and sin, and they cause people to negate the form of the wise soul from seeking truth — which is the service of God and His ethics [which are] good and sweet for anyone with knowledge. And it is not fitting to do [this] on the day of his coming to judgment in front of his Master; to come with a soul darkened and confused from the food and drink, with thoughts of the material which is in it. As we only judge a person according to his deeds of that time. Therefore it is good for him to strengthen his wise soul and to subdue the physical in front of it on this glorious day, so that [the soul] will be fitting and prepared to receive its atonement, and [that] the veil of desires not prevent it.
מִדִּינֵי הַמִּצְוָה. מָה שֶׁאָמְרוּ זִכְרוֹנָם לִבְרָכָה (יומא פ, א), שֶׁשִּׁעוּר הָאֲכִילָה בְּיוֹם הַכִּפּוּרִים לְחַיֵּב עָלֶיהָ דְּאוֹרָיְתָא מֵאֳכָלִין הָרְאוּיִין הוּא כְּכוֹתֶבֶת הַגַּסָּה. וְהַטַּעַם שֶׁנִּשְׁתַּנָּה שִׁעוּר הָאֲכִילָה דְּיוֹם הַכִּפּוּרִים מִשִּׁעוּר שְׁאָר אֲכִילַת אֲסוּרִין שֶׁבַּתּוֹרָה שֶׁהֵן בְּכַזַּיִת, מִפְּנֵי שֶׁהַתּוֹרָה אָסְרָה הָאֲכִילָה בְּאוֹתוֹ הַיּוֹם בִּלְשׁוֹן עִנּוּי, וְלֹא נֶאֱמַר עָלֶיהָ לֹא תֹּאכְלוּ כְּמוֹ בִּשְׁאָר אִסּוּרִין, וּפֵרְשׁוּ חֲכָמִים, שֶׁקִּבְּלוּ הַדְּבָרִים מֵאֲשֶׁר קָדְמוּ לָהֶם, שֶׁאֲכִילָה נִקְרֵאת בְּכַזַּיִת, אֲבָל עִנּוּי הוּא בָּאָדָם, כָּל זְמַן שֶׁלֹּא אָכַל עַד כַּכּוֹתֶבֶת, שֶׁאֵין דַּעַת בֶּן אָדָם מִתְיַשֵּׁב בְּפָחוֹת.
From the laws of the commandment is that which they, may their memory be blessed, said (Yoma 80a) that the measure of eating of fitting foods on Yom Kippur to be liable for it from Torah writ is a large kakotevet. And the reason that the measure of eating of Yom Kippur is differentiated from the measure of eating other prohibitions in the Torah — which are with a kazayit — is because the Torah forbade eating on that day with an expression of affliction. And it does not state, “you shall not eat,” about it, like it states with other prohibitions. And the Sages explained that they received [the tradition] from those that were before them: that with a kazayit, it is called eating; but affliction in a man is so long as he has not eaten a kakotevet — since the mind of a man is not set at ease with less.
וְשִׁעוּר כּוֹתֶבֶת הוּא יוֹתֵר מִגְּרוֹגֶרֶת וּפָחוֹת מִכַּבֵּיצָה, וּפָחוֹת מִשְּׁלֹשָׁה (נ"א מִשְּׁנֵי) זֵיתִים גַּם כֵּן, שֶׁשְּׁלֹשָׁה (נ"א שֶׁשְּׁנֵי) זֵיתִים הֵן כַּבֵּיצָה. כְּלַל הָעִנְיָן כְּבָר דִּקְדֵּק מִי שֶׁהוּא בָּקִי וְשָׁקַל בַּפֶּלֶס, שֶׁאֵין בְּמִשְׁקַל י"ב ארגינ"ץ וְעוֹד שִׁעוּר כַּכּוֹתֶבֶת, וְדִינוֹ כַּחֲצִי שִׁעוּר. וְכֵן מָה שֶׁאָמְרוּ (יומא עג א פ ב) שֶׁשִּׁעוּר הַשְּׁתִיָּה הוּא מְלֹא לֻגְמָיו שֶׁל אָדָם שֶׁהוּא כַּבֵּיצָה שֶׁכְּבָר שִׁעֲרוּ כִּי בֵּיצָה מַחְזִיקָה מְלֹא לֻגְמָיו שֶׁל אָדָם וּבְפָחוֹת מִכֵּן אֵין בּוֹ אִסּוּר כָּרֵת אֶלָּא דִּינוֹ כַּחֲצִי שִׁעוּר, וּלְפִיכָךְ מִי שֶׁהוּא חוֹלֶה אַף עַל פִּי שֶׁאֵין בּוֹ סַכָּנָה גְּמוּרָה, אִם יִהְיֶה חָלוּשׁ הַרְבֵּה רָאוּי לְהַאֲכִילוֹ וּלְהַשְׁקוֹתוֹ מְעַט מְעַט מִכַּשִּׁעוּר שֶׁאָמַרְנוּ, וְנוֹתְנִין רֶוַח בֵּין אֲכִילָה וּשְׁתִיָּה שֶׁל פַּעַם אַחַת לְפַעַם אַחֶרֶת כְּדֵי שִׁעוּר אֲכִילַת פְּרָס, שֶׁהֵן שָׁלֹשׁ בֵּיצִים כְּדַעַת רֹב הַמְּפָרְשִׁים, כְּדֵי שֶׁלֹּא יִצְטָרְפוּ הָאֲכִילוֹת וְתִהְיֶה נֶחְשֶׁבֶת כַּאֲכִילָה אַחַת וְשִׁעוּר אֶחָד, אֲבָל בֵּין הָאֲכִילָה וְהַשְּׁתִיָּה אֵין צָרִיךְ לְהַפְסִיק, שֶׁאֵין מִצְטָרְפִין אֲכִילָה וּשְׁתִיָּה לְעִנְיָן זֶה. וְשִׁעוּר שֶׁבֵּין שְׁתִיָּה לִשְׁתִיָּה כְּדֵי שְׁתִיַּת רְבִיעִית. וּמֻתָּר לִשְׁקֹל וּלְשַׁעֵר דְּבָרִים אֵלּוּ בְּיוֹם הַכִּפּוּרִים לְעֵת הַצֹּרֶךְ, וּמוּטָב נָחוּשׁ וְנַרְחִיק שֶׁלֹּא לֶאֱכֹל שִׁעוּר, וְלֹא נָחוּשׁ לֶאֱסֹר הַמִּשְׁקָל שֶׁהוּא מִדְּרַבָּנָן. וְכֵן מֵעִנְיַן הַמִּצְוָה מָה שֶׁאָמְרוּ זִכְרוֹנָם לִבְרָכָה (שם עז ב) כִּי אֵלּוּ הָעִנּוּיִן שֶׁהֵן דְּרַבָּנָן, כְּגוֹן רְחִיצָה וְסִיכָה, לֹא גָּזְרוּ בָּהֶן רַק שֶׁלֹּא לַעֲשׂוֹתָן שֶׁלֹּא לְצֹרֶךְ, אֲבָל כָּל שֶׁעוֹשֶׂה אוֹתָן לְצֹרֶךְ לֹא גָּזְרוּ, כְּגוֹן מִי שֶׁיֵּשׁ לוֹ חֲטָטִין בְּרֹאשׁוֹ שֶׁסָּךְ כְּדַרְכּוֹ וְאֵינוֹ חוֹשֵׁשׁ, וַאֲפִילּוּ לְנַטּוֹרֵי פֵּירֵי אָמְרוּ זִכְרוֹנָם לִבְרָכָה (שם), שֶׁמֻּתָּר לַעֲבֹר בַּמַּיִם עַד הַצַּוָּאר, וְכָל שֶׁכֵּן לִדְבַר מִצְוָה, בֵּין בַּהֲלִיכָה בֵּין בַּחֲזָרָה.
And the measure of a kotevet (large date) is more than a grogeret (fig cake) and less than a kabeitsah (the size of a large egg) and also less than three (textual variant - two) [large] olives (zayit) — as three (textual variant - two) olives are a kabeitsah. The principle of the matter is that one who is an expert was already exacting and measured on a scale that there is not in the measure of twelve argents and more, the measure of a kakotevet; and [so] its law is like [that of] half a measure. And so [too,] that which they said (Yoma 73a, 80b) that the measure of drinking is the fill of a man’s cheek, which is a kabeitsah — as they have already measured that an egg fills the cheek of a man. And with less than this, there is no prohibition [the liability for which is with] excision. Rather its law is like [that of] half a measure. And therefore [in the case of] someone who is sick — even though there is no full danger with him — if he is very weak; it is fitting to feed him and give him drink little by little, less than the measure that we said. And we give a gap of [time] enough for the eating of a peras (half loaf of bread) — which is three eggs, according to the opinion of most commentators — between the eating and drinking of one time and [that of] another time, so that the eatings not combine and be considered one eating and [hence] one measure. But there is no need to pause between eating and drinking; as eating and drinking do not combine for this matter. And the measure between one drinking and [another] is [time] enough for the drinking of a reviit. And it is permitted to weigh and measure things on Yom Kippur at a time of need. And it is better that we be concerned and distance ourselves to not eat a measure and not be concerned to forbid measuring, which is [only] rabbinic. And also from the matter of the commandment is that which they, may their memory be blessed, said (Yoma 77b) [regarding] these afflictions that are only rabbinic — such as washing and anointing — they only decreed that they should not be done for no need. But they did not decree [about] anyone who does them for a need — for example, one who has scabs on his head [may] anoint them in his [customary] way and not be concerned. And they, may their memory be blessed (Yoma 77b), said that it is permitted to cross water until the neck even to guard fruits — and all the more so, for the matter of a commandment — whether going or returning.
וּבְעִנְיַן הַסַּנְדָּל פֵּרְשׁוּ לָנוּ מוֹרֵינוּ יִשְׁמְרֵם אֵל, שֶׁסַּנְדָּל הוּא בְּכָל מָקוֹם שֶׁל עוֹר, וְזֶהוּ שֶׁאָסוּר בְּיוֹם הַכִּפּוּרִים, אֲבָל לֹא שֶׁל מִין אַחֵר, וּכְלָלָא דְּמִלְּתָא לְפִי קְצָת הַפֵּרוּשִׁים דְּכָל שֶׁהוּא רָאוּי לְעִנְיַן חֲלִיצָה, כְּלוֹמַר שֶׁהוּא שֶׁל עוֹר הוּא אָסוּר בְּיוֹם הַכִּפּוּרִים וּמֻתָּר לָצֵאת בּוֹ בְּשַׁבָּת לִרְשׁוּת הָרַבִּים, וְכָל שֶׁאֵינוֹ רָאוּי לַחֲלִיצָה, כְּגוֹן שֶׁל שַׁעַם וְגֶמִי וְהוּצֵי (עי' יומא עח ב דהוא סנדל של עשבים) וּשְׁאָר מִינֵי עֲשָׂבִים מֻתָּרִין בְּיוֹם הַכִּפּוּרִים, וּבִלְבַד שֶׁלֹּא יֵצֵא בָּהֶם לְמָקוֹם שֶׁאֵינוֹ מְעֹרָב דְּמַשּׂאוֹי חָשְׁבִינַן לְהוּ. וּמִן הַמְּפָרְשִׁים רַבִּים וְנִכְבָּדִים, מַתִּירִין לָצֵאת בְּכֻלָּן בִּרְשׁוּת הָרַבִּים.
And concerning the shoe (sandal), our teachers — God should protect them — explained that a shoe is always of leather. And that is what is forbidden on Yom Kippur, but not of a different type. And the principle of the matter according to some commentators is that anything that is fitting for the matter of release (chalitsah) — meaning to say, that it is of leather — is forbidden on Yom Kippur, and permitted to go out into a public domain with them (wearing them) on Shabbat. But anything that is not fitting for release — such as cork and reeds and palms (see Yoma 78b, that it is a shoe of grasses) and other types of grasses (plants) — are permitted on Yom Kippur, so long as they do not go out with them [to a public domain] in a place without an eruv, as we consider them like a burden (and not a piece of clothing, which is permitted). But from the commentators, there are [also] many honored ones that permit one to go out into the public domain with all of them.
וְדִין חוֹלֶה (יומא פג, א) שֶׁיֵּשׁ בּוֹ סַכָּנָה שֶׁמַּאֲכִילִין אוֹתוֹ עַל פִּי רוֹפֵא בָּקִי, אוֹ עַל פִּי עַצְמוֹ וַאֲפִלּוּ רוֹפֵא אוֹמֵר אֵינוֹ צָרִיךְ וְדִין עֻבָּרָהּ (שם פב א פג א) שֶׁהֵרִיחָה, וְדִין מִי שֶׁאֲחָזוֹ בֻּלְמוֹס, וְדִין קְטַנִּים בֵּין תִּינוֹק בֵּין תִּינֹקֶת מֵאֵיזֶה זְמַן מְעַנִּין אוֹתָן כָּל הַיּוֹם מִדְּרַבָּנָן, וְכֵן מֵאֵיזֶה זְמַן מְחַנְּכִין אוֹתָן לְשָׁעוֹת, וּכְלָלָא דְּמִלְּתָא לְפִי קְצָת מִן הַמְּפָרְשִׁים, דִּשְׁתֵּי שָׁנִים קֹדֶם גַּדְלוּת בְּבָרִיא מַשְׁלִימִין מִדְּרַבָּנָן, וּשְׁתֵּי שָׁנִים קֹדֶם לְכָךְ מְחַנְּכִין אוֹתָם לְשָׁעוֹת. וְיֵשׁ שֶׁפֵּרְשׁוּ שָׁנָה אַחַת קֹדֶם גַּדְלוּת מַשְׁלִימִין מִדְּרַבָּנָן בֵּין תִּינוֹק בֵּין תִּינֹקֶת, וְיֵשׁ שֶׁפֵּרְשׁוּ שֶׁאֵין מַשְׁלִימִין מִדְּרַבָּנָן רַק בְּתִינֹקֶת לְבַד שָׁנָה אַחַת קָדַם גַּדְלוּת, אֲבָל תִּינוֹק אֵינוֹ מַשְׁלִים כְּלָל מִדְּרַבָּנָן, וְגַדְלוּת הוּא בְּתִינוֹק, שְׁלֹשׁ עֶשְׂרֵה שָׁנָה וְיוֹם אֶחָד, וּבְתִינֹקֶת שְׁתֵּים עֶשְׂרֵה שָׁנָה וְיוֹם אֶחָד. וְהַמֶּלֶךְ וְהַכַּלָּה בִּרְחִיצָה בְּיוֹם זֶה מָה דִּינָן (יומא עג ב).
And the law of the sick person who is in danger, that we feed him according to an expert physician, or according to himself — and even if the physician says that he does not need [to eat] (Yoma 83a); the law of a pregnant woman that smelled [food] (Yoma 82a, 83a); the law of one who was seized by bulimia; and the law of minors — whether a boy or a girl from what time do we we afflict them all of the day rabbinically, and likewise from when do we teach them [to fast] with [some] hours. And the principle of the matter according to a few of the commentators is that two years before the adulthood of a healthy child, they complete [the fast] rabbinically; and two years before that, we teach them [to fast] with [some] hours. And some explained that it is one year before adulthood that they complete [the fast] rabbinically — whether a boy or a girl. And some explained that only a girl alone completes [the fast] rabbinically one year before adulthood, but a boy does not complete [the fast] at all rabbinically. And adulthood for a boy is thirteen years and a day, and for a girl is twelve years and a day. And what is the law about washing for the king and the bride on this day (Yoma 73b).
וְעוֹד אַזְכִּיר לְךָ כָּאן מַה שֶׁאָמְרוּ זִכְרוֹנָם לִבְרָכָה גַּם כֵּן בְּעִנְיַן תַּעֲנִית תִּשְׁעָה בְּאָב הַיָּדוּעַ שֶׁהוּא מִדְּרַבָּנָן, וְאַף עַל פִּי שֶׁרְחוֹקִים מְאֹד שְׁנֵי הַיָּמִים אֵלֶּה בְּטַעְמָן וּבְכָל עִנְיָנָם, לְפִי שֶׁשֵּׁם תַּעֲנִית כּוֹלְלָם נְדַבֵּר בּוֹ מְעַט. וְאוֹדִיעֲךָ שֶׁהֶחְמִירוּ בּוֹ חֲכָמִים בְּכָל עִנְיָנוֹ כְּמוֹ בְּיוֹם הַכִּפּוּרִים לְהַפְסִיק מִבְּעוֹד יוֹם, וּבְסִיכָה, וּבִנְעִילַת הַסַּנְדָּל, וּבְתַשְׁמִישׁ הַמִּטָּה, וְעֻבָּרוֹת וּמְנִיקוֹת שֶׁמִּתְעַנּוֹת בּוֹ כִּשְׁאָר הָעָם, מָה שֶׁאֵין עוֹשׂוֹת כֵּן בְּכָל שְׁאָר תַּעֲנִיּוֹת, חוּץ מִשָּׁלֹשׁ תַּעֲנִיּוֹת אֶמְצָעִיּוֹת שֶׁל עֲצִירַת מָטָר, כְּמוֹ שֶׁנִּזְכַּר בְּמַסֶּכֶת תַּעֲנִית בְּסוֹף פֶּרֶק רִאשׁוֹן (יד, א), דְּאַסִּיק רַב אַשֵׁי הָתָם, נְקֹט מְצִיעֲתָא בִּידָךְ. וְיֶתֶר פְּרָטֵי מִצְוָה זוֹ, מְבֹאָרִים בְּמַסֶּכֶת יוֹמָא [א"ח סי' תריב].
And I will further mention to you here that which they, may their memory be blessed, said about the matter of the 9th of Av, which is well-known to be rabbinic. And even though these two days are very distant in their reasons and their content; since the word, “fast,” includes [both of] them, we will speak a little about it. And I will inform you that the Sages were stringent about it in all of its content like on Yom Kippur — to stop [eating] while it is still [the previous] day, and [about] anointing, wearing shoes and sexual relations. And pregnant and nursing women fast like the rest of the people - which they do not do on all other fasts, except for the middle three fasts of the stopping of rain. [This is] as it is mentioned in Tractate Taanit 14a at the end of the first chapter, where Rav Ashi concludes, “Take the middle [one] in your hand.” And the rest of the details of the commandment [of fasting on Yom Kippur] are elucidated in Tractate Yoma. (See Tur, Orach Chaim 612.)
וְנוֹהֶגֶת בְּכָל מָקוֹם וּבְכָל זְמַן בִּזְכָרִים וּנְקֵבוֹת, וְהָעוֹבֵר עַל זֶה וְאָכַל בְּיוֹם הַכִּפּוּרִים כְּשִׁעוּר הַכּוֹתֶבֶת בִּטֵּל עֲשֵׂה, וְעָבַר עַל לָאו שֶׁיֵּשׁ בּוֹ כָּרֵת, שֶׁנֶּאֱמַר כִּי כָל הַנֶּפֶשׁ אֲשֶׁר לֹא תְעֻנֶּה בְּעֶצֶם הַיּוֹם הַזֶּה וְנִכְרְתָה. אָכַל אוֹ שָׁתָה כְּשִׁעוּר זֶה בִּשְׁגָגָה חַיָּב קָרְבַּן חַטָּאת קְבוּעָה.
And [it] is practiced in every place and at all times by males and females. And one who transgresses it and ate like the measure of a kotevet on Yom Kippur has violated a positive commandment, and has [also] transgressed a negative commandment that has [a liability of] excision for it; as it is stated (Leviticus 23:29), “For any soul which is not afflicted on that very day shall be excised.” [If] he ate or drank like this measure inadvertently, he is liable for a fixed sin-offering.