Sefer HaBahir 70

1[Rabbi Rachumai continued,] "And why does it say, 'I am awed' (Habakkuk 3:2)? Because an ear is in the image of Aleph, and Aleph is the head of all letters. Further, Aleph causes all of the other letters to stand, and Aleph is the image of the brain. Just as Aleph, when you pronounce her, you open your mouth, so too, thought, when you think toward endlessness and boundlessness.* From the Aleph, all the letters come out. Do you not see that she is the first of them? And it says, 'YHVH is at their head' (Micah 2:13). It establishes for us that every name that is written with Yud Hei Vav Hei is set apart [מיוחד] for the Blessed Holy One and sanctified in holiness. What is in holiness? The holy palace. And where is the holy palace? You must say: in thought. And this is Aleph, as is written, 'YHVH, I have understood** Your renown; I am awed' (Habakkuk 3:2).*[More literally, "toward no end or limit."]**[See previous, #69.]