Iob was the third son of Issachar. In parallel genealogical passages, the same person or family is called Jashub, a form also supported by the versions in Genesis.
Iob is named in the genealogy of Issachar in Genesis. The parallel records in Numbers and 1 Chronicles use the name Jashub, making the identification of the name significant for comparing the genealogical lists.
The name appears in differing forms in the genealogical records: Iob in Genesis and Jashub in Numbers and 1 Chronicles. The latter is presented as probably the more correct form.