Likutei Moharan 10:7/ליקוטי מוהר"ן י׳:ז׳

17. The Torah, too, corresponds to hands and feet. For the Torah consists of both revealed and hidden [teachings]. The revealed corresponds to the hands, as in, “My beloved put his hand in through the chor (hole).” “In by the ChoR” alludes to “ChoRut (engraved) on the tablets” (Exodus 32:16) —this being the revealed. The hidden corresponds to the feet, as our Sages said: “The rounded thighs” (Song of Songs 7:2) —just as the thigh is hidden, so too, the words of Torah (Sukkah 49b).

2And the Torah in its entirety is called lev (heart), because it begins with a Bet and concludes with a Lamed. [The heart] is the dwelling place of the spirit “which blows in the six sections of the arms and the six sections of the legs”—i.e., in the revealed and the hidden.