Who was Ahimelech?
Ahimelech was the father of David's high priest Abiathar: son of Ahitub, the son of Phinehas, the son of Eli (1 Samuel 21:1 , 1 Samuel 21:2 , 1 Samuel 21:8 ; 1 Samuel 22:9-20 ; 1 Samuel 23:6 ; 1 Samuel 30:7 ). Ahijah the son of Ahitub (1 Samuel 14:3 , 1 Samuel 14:18 ) was either the same person under another name, or was Ahimelech's father or brother.
Ahimelech is an interesting person, especially because he stands for whatever information we have concerning the priestly office in Israel during the period between Eli and David. Whether the Deuteronomic law for a central sanctuary originated with Moses or not, its provisions were very imperfectly carried out during the times of the Judges.
This was particularly the case after the capture of the ark by the Philistines, and the deaths of Eli and his sons. From that time to the middle of the reign of David the ark was in the custody of the men of Kiriath-jearim "in the hill," or "in Gibeah" (1 Samuel 7:1 ; 2 Samuel 6:2 , 2 Samuel 6:3 ). As a general proposition Israel "sought not unto it" (1 Chronicles 13:3 ), though there is nothing to forbid the idea that it may, on occasion, have been brought out from its seclusion (1 Samuel 14:18 ).
Before and after the accession of Saul some of the functions of the national sanctuary were transacted, of course very incompletely, at Gilgal (1 Samuel 10:8 ; 1 Samuel 11:14 , 1 Samuel 11:15 ; 1 Samuel 13:7 ; 1 Samuel 15:12 , 1 Samuel 15:21 , 1 Samuel 15:33 ). Whether there was a priesthood, with Ahitub the grandson of Eli as high priest, is a matter on which we have no information; but we may remind ourselves that the common assumption that such men as Samuel and Saul performed priestly offices is nothing but an assumption.
After Saul has been king for a good many years we find Ahijah in his retinue, acting as priest and wearing priestly vestments. A few years later Ahimelech is at the head of the very considerable priestly establishment at Nob. The scale on which it existed is indicated by the fact that 85 robed priests perished in the massacre (1 Samuel 22:18 ). They had families residing at Nob (1 Samuel 22:19 ). They were thought of as priests of Yahweh, and were held in reverence (1 Samuel 22:17 ). It was a hereditary priesthood (1 Samuel 22:11 , 1 Samuel 22:15 ).
Men deposited votive offerings there, the sword of Goliath, for example (1 Samuel 21:9 ). There seems to have been some kind of police authority, whereby a person might be "detained" (1 Samuel 21:7 ). It was customary to inquire of Yahweh there (1 Samuel 22:10 , 1 Samuel 22:15 ). A distraction was made between the common and the holy (1 Samuel 21:4-6 ). The custom of the shewbread was maintained (1 Samuel 21:6 ). In fine, Jesus is critically correct in calling the place "the house of God" (Mark 2:26 ).
The account does not say that the ark was there, or that the burnt-offering of the morning and evening was offered, or that the great festivals were held. The priestly head of the establishment at Nob is represented to have been the man who had the right to the office through his descent from Aaron. It is gratuitous to assume that there were other similar sanctuaries in Israel, though the proposition that there were none might be, like other negative propositions, hard to establish by positive proof.
IBSE, "Ahimelech" (in the public domain) with minor edits.