Ben Asher was descended from a long line of Masoretes, starting with someone called Asher, but nothing is known about them other than their names. His father, Moses ben Asher, is credited with writing the Cairo Codex of the Prophets (895 CE). If authentic, it is among the oldest manuscripts containing a large proportion of the Hebrew Bible. Umberto Cassuto used this manuscript as the basis of his edition of the Hebrew Bible. Aaron ben Asher himself added vowelization and cantillation notes, and mesorah to the Aleppo Codex, correcting its letter-text according to the masorah.