The Powers of God
“Moreover, a large part of the book consists of mystical variations on motifs from the Book Yesirah. In fact, the term sefiroth was taken by the Bahir from that work, though it is no longer understood in the sense of ideal numbers that contain within them all the powers of creation, as was the case with the author of the Yesirah.
The sefiroth now signify the aeons, the powers of God, which are also his attributes. The term sefiroth, however, does not occupy an important place in the Bahir. It appears only in section 87, where the ten fingers raised in the benediction of the priests are found to be “an allusion to the ten sefiroth by means of which heaven and earth are sealed.”
In the Book Yesirah itself, only six of the sefiroth perform this function, and in this particular instance the term is evidently identified with a different conception. This is also indicated by the book’s new explanation of the meaning of the term sefiroth.
The word is not derived from safar, to count, but from sappir, sapphire. They are thus sapphirine reflections of the divinity, and Psalm 19:2: “The heavens declare the glory of God,” is interpreted by the author in accordance with this etymology: “the heavens shine in the sapphirine splendor of the glory of God.”
This mystical etymology subsequently became classic in kabbalistic literature. In view of the fragmentary condition of the book, it may not be possible to infer very much from the fact that the term sefiroth is missing in other parts of the text. It nevertheless remains surprising that the notion of the sefiroth was, so to speak, eliminated from just those passages that are very clearly based upon the Book of Creation, but appears as something known and self-evident in precisely a passage that otherwise has no connection with the motifs of the Book Yesirah.
Instead, these aeons, if we may speak of them as such, are described in completely different terms. These names reflect the fullness of meaning and “multivalence” of the aeons in gnostic mythology. They are, as we have seen, the powers of God.”
Gershom Scholem, Origins of the Kabbalah, pp. 81-2.