1 Samuel 2:30

When Abiathar, the descendant of Eli, fled to David (1 Samuel 22:20), Zadok, a descendant of Eleazar, may have been made chief priest by Saul. He appears soon after, and it is not known how or when the office was bestowed on him. David divided the dignity between the two (2 Samuel 8:17), but Abiathar was deposed by Solomon (1 Kings 2:27), and the priesthood remained with Zadok and his descendants down to the time of the exile. Thus the prophet's threat was fulfilled.

31-35. It is keenly disputed to what events these vv refer. The simplest explanation is that 1 Samuel 2:31 refers to the massacre of the priests at Nob, 1 Samuel 2:32 to the deposition and consequent poverty of Abiathar, and 1 Samuel 2:35 to Zadok.