  Two other short treatises have each a peculiar focus. Sefer ha-Shem is an enigmatic treatise on God’s proper names written out with the Hebrew letters AHYH and YHWH. The basic idea is that the special properties of the numbers associated with these letters, their phonetic qualities, grammatical functions and graphic representations, all convey information about the godhead. Thus, for instance, one (A, aleph) is the foundation of number, but not a number itself; both five (H, heh) and six (W, waw) repeat themselves as the final digit in all higher powers; and ten (Y, yod) is the beginning of the next order in the decimal system. All this seems to indicate the unchanging aspect of the divine in its successive manifestations. The same collection of ideas is found in non-philosophical writings, for example, the grammatical treatise Sefer Zahut.