Chapter 6, Verse 6

6. These are the twenty-two letters with which engraved Ehyeh, Yah, YHVH Elohim, YHVH, YHVH Tzavaot, Elohim Tzavaot, El Shaddai, YHVH Adonoy, and with them He made three books, and with them He created His universe, and He formed with them all that was ever formed, and all that ever will be formed.

We have now come full circle from the very first verse of the Sefer Yetzirah. The description is finished regarding how we and God create something from something (yesh m'yesh) through permutations and manipulations of fundamental forces. God also creates something from nothing (yesh m'ayin), but it is up to us to take what is given and manipulate it in order to release the holiness contained within.