"The Story of Joseph" is a running narrative, but the exoteric commentaries fill in gaps in the story, make connections and identifying characters. Adding detail to the novella is not uncommon, and most complement information already known from the holy texts. According to the Encyclopedia of Iranic, much of this comes from the Esra'Illiyat, that is, traditions drawn from the body of knowledge about Biblical events and people shared by Christians, Jews, and early Muslims. A fairly consistent source for this tradition goes back to the authority of Ibn 'Abbas (d. ca. 687) or Esma'il b. 'Abd-al-Rahman Soddi (d. 745).