To not build [with] hewn stones: That we should not build an altar of stones that metal would touch, as it is stated (Exodus 20:22), “do not build of hewn (gazit) stones.” The explanation of hewn (Ramban on Exodus 20:22) is when we chisel from the stone with an iron tool. And if [the altar] is built with hewn stones, it is disqualified.
It is from the roots of this commandment that we should fix into our souls from the day that we make [the altar], that forgiveness of iniquity, blessing and peace will come [through] it afterwards. And hence to remember this thing, we were commanded to not do anything upon it with tools that are fit for destruction — and that is [those made from] iron that cuts and is constantly ready to spill blood. And I have already prefaced for you at the beginning, that man is acted upon according to his actions, and [that] his thoughts always follow his deeds. Therefore, it is fitting for us to do symbolic actions, according to the intention of the things. And when the fool who is [too] rushed hears these things, he will not know nor understand [them].
The laws of the commandment — for example, from where they would bring these stones with which they would build the altar, that they, may their memory be blessed, said (Mishnah Middot 3:4) that they would bring them from virgin ground or from the Great Sea; the law of if metal touched a stone after the altar was built, whether all of it is disqualified or only it alone is disqualified; that which they, may their memory be blessed, said (Mishnah Middot 3:4), [that] when they whitewashed the altar twice a year, that they did not whitewash it with a tool that had iron in it, so that iron would not touch a stone; and the rest of its details — are [all] elucidated in Tractate Middot. (See Mishneh Torah, Laws of The Chosen Temple 1.)
And [it] is practiced at the time of the [Temple] by males and females. And one that transgresses it and builds the altar or [its] ramp with a stone that iron touched is lashed.
שֶׁלֹּא לִבְנוֹת אַבְנֵי גָּזִית – שֶׁלֹּא נִבְנֶה מִזְבַּח אֲבָנִים שֶׁיִּגַּע בָּהֶן בַּרְזֶל. שֶׁנֶּאֱמַר (שמות כ כב) לֹא תִבְנֶה אֶתְהֶן גָּזִית, פֵּרוּשׁ גָּזִית (רמב"ן שם) הוּא כְּשֶׁפּוֹסְלִין מִן הָאֶבֶן בִּכְלִי בַּרְזֶל. וְאִם נִבְנָה בְּאַבְנֵי גָּזִית, פָּסוּל.
To not build [with] hewn stones: That we should not build an altar of stones that metal would touch, as it is stated (Exodus 20:22), “do not build of hewn (gazit) stones.” The explanation of hewn (Ramban on Exodus 20:22) is when we chisel from the stone with an iron tool. And if [the altar] is built with hewn stones, it is disqualified.
מִשָּׁרְשֵׁי מִצְוָה זוֹ, שֶׁנִּקְבַּע בְּנַפְשׁוֹתֵינוּ מִיּוֹם עֲשׂוֹתוֹ שֶׁבְּסִבָּתוֹ תָּבֹא לָנוּ מְחִילַת הֶעָוֹן וְהַבְּרָכָה וְהַשָּׁלוֹם אַחֲרֵי כֵן, וְעַל כֵּן לְזֵכֶר זֶה הַדָּבָר נִצְטַוִּינוּ שֶׁלֹּא לַעֲשׂוֹת בּוֹ דָּבָר בְּכֵלִים הַמּוּכָנִים לְהַשְׁחָתָה, וְזֶהוּ הַבַּרְזֶל שֶׁכּוֹרֵת וּמוּכָן תָּמִיד לִשְׁפֹּךְ דָּם. וּכְבָר הִקְדַּמְתִּי לְךָ בַּתְּחִלָּה כִּי הָאָדָם נִפְעָל כְּפִי פְּעֻלּוֹתָיו, וּמַחְשְׁבוֹתָיו הוֹלְכוֹת לְעוֹלָם אַחֲרֵי מַעֲשָׂיו, עַל כֵּן רָאוּי לָנוּ לַעֲשׂוֹת דִּמְיוֹנוֹת הַפְּעֻלּוֹת כְּפִי כַּוָּנַת הַדְּבָרִים. וְהַסָּכָל הַמַּהְבִּיל הַשּׁוֹמֵעַ דְּבָרִים אֵלֶּה לֹא יֵדַע וְלֹא יָבִין.
It is from the roots of this commandment that we should fix into our souls from the day that we make [the altar], that forgiveness of iniquity, blessing and peace will come [through] it afterwards. And hence to remember this thing, we were commanded to not do anything upon it with tools that are fit for destruction — and that is [those made from] iron that cuts and is constantly ready to spill blood. And I have already prefaced for you at the beginning, that man is acted upon according to his actions, and [that] his thoughts always follow his deeds. Therefore, it is fitting for us to do symbolic actions, according to the intention of the things. And when the fool who is [too] rushed hears these things, he will not know nor understand [them].
דִּינֵי הַמִּצְוָה, כְּגוֹן מֵהֵיכָן הָיוּ מְבִיאִין אוֹתָן הָאֲבָנִים שֶׁבּוֹנִין בָּהֶן הַמִּזְבֵּחַ, שֶׁאָמְרוּ ז"ל (מדות ג ד) כִּי מִן בְּתוּלַת קַרְקַע אוֹ מִן הַיָּם הַגָּדוֹל הָיוּ מְבִיאִין אוֹתָן, וְדִין אִם נָגַע בַּרְזֶל בְּאֶבֶן אַחַר שֶׁנִּבְנֵית בַּמִּזְבֵּחַ אִם פּוֹסֶלֶת הַכֹּל אוֹ הִיא לְבַדָּהּ פְּסוּלָה, וּמָה שֶׁאָמְרוּ ז"ל (שם) כְּשֶׁמְּלַבְּנִין אֶת הַמִּזְבֵּחַ פַּעֲמַיִם בַּשָּׁנָה שֶׁלֹּא יְלַבְּנוּהוּ בִּכְלִי שֶׁיְּהֵא בּוֹ בַּרְזֶל כְּדֵי שֶׁלֹּא יִגַּע הַבַּרְזֶל בָּאֶבֶן, וְיֶתֶר פְּרָטֶיהָ מְבֹאָרִים בְּמַסֶּכֶת מִדּוֹת. (ה' בית הבחירה פ"א).
The laws of the commandment — for example, from where they would bring these stones with which they would build the altar, that they, may their memory be blessed, said (Mishnah Middot 3:4) that they would bring them from virgin ground or from the Great Sea; the law of if metal touched a stone after the altar was built, whether all of it is disqualified or only it alone is disqualified; that which they, may their memory be blessed, said (Mishnah Middot 3:4), [that] when they whitewashed the altar twice a year, that they did not whitewash it with a tool that had iron in it, so that iron would not touch a stone; and the rest of its details — are [all] elucidated in Tractate Middot. (See Mishneh Torah, Laws of The Chosen Temple 1.)
וְנוֹהֶגֶת בַּזְּמַן הַבַּיִת בִּזְכָרִים וּנְקֵבוֹת, וְהָעוֹבֵר עָלֶיהָ וּבָנָה אֶבֶן שֶׁנָּגַע בָּהּ בַּרְזֶל בַּמִּזְבֵּחַ אוֹ בַּכֶּבֶשׁ, לוֹקֶה.
And [it] is practiced at the time of the [Temple] by males and females. And one that transgresses it and builds the altar or [its] ramp with a stone that iron touched is lashed.