Abiathar was a priest who had joined David following the massacre at Nob (cf. 1 Samuel 22:6–23). He was with David for most of his fugitive days (1 Samuel 23:6, 1 Samuel 23:9, 1 Samuel 30:7, 1 Kings 2:26). Eventually, after David came to power, he would also occupy the position of high priest along with Zadok (2 Samuel 20:25). Later, however, he would be banished by Solomon for siding with Adonijah (1 Kings 1:7).
7 And David said to Abiathar the priest, the son of Ahimelech, “Bring me the ephod.” So Abiathar brought the ephod to David.