Shlach Lecha: Chapter 18
Letters soaring

We hear of the birds that rise and descend, rise and descend, and are told that these are the great and the small letters. When the letters fly, a person sees written in the air temporarily, in great letters, "In the beginning Elohim created...", followed by the other sayings in the acts of creation. The author says that whoever preserves the covenant places himself to follow the Shechinah and is guarded from behind by the supernal righteous, with great love. We hear that when the firmament revolves it performs music from the sound of the waters that flow, but the lower grades are not capable of hearing it. Whoever deserves to receive from those waters stands there in happiness and in awe, since both come from serving God.