from
Easton's 1897 Bible Dictionary
Abiathar
father of abundance, or my father excels, the son of Ahimelech
the high priest. He was the tenth high priest, and the fourth in
descent from Eli. When his father was slain with the priests of
Nob, he escaped, and bearing with him the ephod, he joined
David, who was then in the cave of Adullam (1 Sam. 22:20-23;
23:6). He remained with David, and became priest of the party of
which he was the leader (1 Sam. 30:7). When David ascended the
throne of Judah, Abiathar was appointed high priest (1 Chr.
15:11; 1 Kings 2:26) and the "king's companion" (1 Chr. 27:34).
Meanwhile Zadok, of the house of Eleazar, had been made high
priest. These appointments continued in force till the end of
David's reign (1 Kings 4:4). Abiathar was deposed (the sole
historical instance of the deposition of a high priest) and
banished to his home at Anathoth by Solomon, because he took
part in the attempt to raise Adonijah to the throne. The
priesthood thus passed from the house of Ithamar (1 Sam.
2:30-36; 1 Kings 1:19; 2:26, 27). Zadok now became sole high
priest. In Mark 2:26, reference is made to an occurrence in "the
days of Abiathar the high priest." But from 1 Sam. 22, we learn
explicitly that this event took place when Ahimelech, the father
of Abiathar, was high priest. The apparent discrepancy is
satisfactorily explained by interpreting the words in Mark as
referring to the life-time of Abiathar, and not to the term of
his holding the office of high priest. It is not implied in Mark
that he was actual high priest at the time referred to. Others,
however, think that the loaves belonged to Abiathar, who was at
that time (Lev. 24:9) a priest, and that he either himself gave
them to David, or persuaded his father to give them.