Sefer Yetzirah
Sefer Yetzirah (Hebrew: סֵפֶר יְצִירָה Sēp̄er Yəṣīrā, Book of Formation, or Book of Creation) is a work of Jewish mysticism. Early commentaries, such as the Kuzari, treated it as a treatise on mathematical and linguistic theory, as opposed to one about Kabbalah.