The deeds that are perfected by devoting them to G-d alone while performing them are the acts of service whereby one hopes to find favor with G-d. These deeds are all the visible mitzvot (commandments) of the physical limbs. For it is possible to perform them without intent for G-d, such as to do them in order to appear important in the eyes of others, or to hope for their honor and praise.
But for the duties of the heart, there can be no hypocrisy, nor expectation of honor, respect, or praise on account of fulfilling them since other people cannot look into one's heart. Therefore one's intent in fulfilling them is automatically only to the Watcher, namely, the blessed Creator alone, as written "I, the L-rd, search the heart, examine the reins.." (Yirmiya 17:10), and "the hidden things belong to the L-rd our G-d" (Devarim 29:28).
אֲבָל הַמַּעֲשִׂים אֲשֶׁר יֻשְׁלְמוּ בְּיַחֲדָם לָאֵל בְּעֵת עֲשׂוֹתָם הֵם מַעֲשֵׂי הָעֲבוֹדָה שֶׁמְּקַוִּים בָּהֶם רְצוֹן הָאֱלֹהִים וְהֵם כָּל הַמִּצְוֹת הַנִּרְאוֹת עַל הָאֵבָרִים שֶׁאֶפְשָׁר שֶׁתִּהְיֶה הַכַּוָּנָה בָּהֶם לְזוּלַת הָאֵל, וְתִהְיֶה כַּוָּנַת עוֹשֵׂיהֶם לְהִזְדַּיֵּן בָּהֶן אֵצֶל בְּנֵי אָדָם וּלְקַוּוֹת כְּבוֹדָם וְשִׁבְחָם עַל עֲשׂוֹתָם,
The deeds that are perfected by devoting them to G-d alone while performing them are the acts of service whereby one hopes to find favor with G-d. These deeds are all the visible mitzvot (commandments) of the physical limbs. For it is possible to perform them without intent for G-d, such as to do them in order to appear important in the eyes of others, or to hope for their honor and praise.
אֲבָל חוֹבוֹת הַלְּבָבוֹת לֹא יִתָּכֵן בָּהֶם חֹנֶף וְלֹא כָּבוֹד וְלֹא שֶׁבַח לְמִי שֶׁמְּקַיֵּם מֵהֶם דָּבָר מִפְּנֵי שֶׁאֵין ב״א יוֹדְעִים אֶת לְבָבוֹ אַךְ הוּא מְכַוֵּן בָּהֶם לְשֵׁם הַמַּשְׁקִיף וְהוּא הַבּוֹרֵא יִתְבָּרַךְ בִּלְבַד כְּמוֹ שֶׁאָמַר (ירמיהו י״ז:י׳) אֲנִי ה׳ חֹקֵר לֵב בֹּחֵן כְּלָיוֹת וְאָמַר (דברים ל) הַנִּסְתָּרוֹת לַה׳ אֱלֹהֵינוּ וְגוֹ׳:
But for the duties of the heart, there can be no hypocrisy, nor expectation of honor, respect, or praise on account of fulfilling them since other people cannot look into one's heart. Therefore one's intent in fulfilling them is automatically only to the Watcher, namely, the blessed Creator alone, as written "I, the L-rd, search the heart, examine the reins.." (Yirmiya 17:10), and "the hidden things belong to the L-rd our G-d" (Devarim 29:28).