Then the king said to Abiathar the priest, “Go back to your fields in Anathoth. Even though you deserve to die, I will not put you to death at this time, since you carried the ark of the Lord GOD before my father David, and you suffered through all that my father suffered.”
Abiathar and Joab were both aiding and abetting in Adonijah's rebellious attempt, and it is probable were at the bottom of this new motion made of Adonijah for Abishag, and it should seem Solomon knew it, Kg1 2:22. This was, in both, an intolerable affront both to God and to the government, and the worse because of their high station and the great influence their examples might have upon many.
Commenting on 1 Kings 2:26-34
So Solomon thrust out Abiathar from being priest unto the Lord,.... He deposed him from his office of high priest, otherwise I suppose he might officiate as a common priest, at least in some of the branches of it; this was done by his own authority as a king, and not as a prophet, as Bellarmine vainly distinguishes; and not by the authority of the...
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.