Jamieson, Fausset and Brown on 1 Kings 2:26-27

26-27. unto Abiathar the priest said the king--This functionary, as the counsellor or accomplice of Adonijah, had deserved to share his fate. But partly from regard to his priestly dignity, and partly from his long associations with the late king, Solomon pronounced on him the mitigated sentence of banishment to his country estate at Anathoth, and thereby, as God's vicegerent, deprived him of his office and its emoluments. The sacred writer notices the remarkable fulfilment, Abiathar's degradation from the high priesthood (see on 1Ki 4:4), of the doom denounced against the house of Eli (1Sa 2:30).

1Ki 2:28-45. Joab Slain.