SEFER YETSIRAH (Book of creation) is an ancient Jewish cosmogonical and cosmological treatise that forms part of the literature of Qabbalah; falsely attributed to Abraham the patriarch and to ʿAqivaʾ ben Yosef, a second-century tanna. Composed of six short chapters, it describes God's creation of the world by means of the ten cosmic numbers (sefirot) and the twenty-two letters of the Hebrew alphabet.

The date of composition of Sefer yetsirah is the subject of controversy among scholars. Gershom Scholem assigns it to the tannaitic period (second to third centuries CE), whereas N. Aloni argued that it is a work of the eighth or ninth century, written under the influence of Arabic linguistics. The treatise is extant in two main versions, one short and one long, without major divergences in ideas between them. It has been translated into several European languages.

A major contribution of Sefer yetsirah...