This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
The Sepher Yetzirah, the Book of Formation, is among the oldest surviving Hebrew texts to treat the alphabet itself as a cosmological structure, assigning the twenty two Hebrew letters a role in creation and grouping them by their own internal logic, mothers, doubles and elementals, a documented foundation the later, more explicitly numerical practice of gematria built directly upon.
That foundational text matters for a numerology system entry because Hebrew gematria's own numeric values for the twenty two letters did not arise in isolation from this older letter mysticism, and an entry can record honestly that gematria's practice of summing a word's letters to find significance in the total continues a documented older tradition of treating the Hebrew alphabet as inherently meaningful, not simply as a late invention layered onto an otherwise ordinary alphabet.
An entry keeps the text's own uncertain authorship and disputed dating honestly stated, since the Sepher Yetzirah is traditionally attributed to the patriarch Abraham but survives only in manuscripts scholars date many centuries later, and states clearly which specific claim about gematria's method traces to this documented early text and which belongs to a later medieval or modern elaboration of it.