Albert Barnes Commentary 1 Samuel 14:3

"and Ahijah, the son of Ahitub, Ichabod`s brother, the son of Phinehas, the son of Eli, the priest of Jehovah in Shiloh, wearing an ephod. And the people knew not that Jonathan was gone." — 1 Samuel 14:3 (ASV)

It is impossible to say with certainty whether "Ahiah" (or "Ahijah") is the same person as "Ahimelech the son of Ahitub," or if Ahimelech was the brother or son of Ahijah and his successor in the priesthood.

Most likely, "Ahijah" and "Ahimelech" are variations of the same name, with only the latter element of each name being different: מלך melek (king) is substituted for the divine name יה yāh. For comparison, see "Eliakim" and "Jehoiakim" in 2 Kings 23:34, or "Eliab" and "Eliel" in 1 Chronicles 6:27 and 1 Chronicles 6:34.

This genealogical fragment is a very valuable aid to the chronology. The high priest at this time was the grandson of Phinehas, the son of Eli. Samuel, who was now an old man, was likely a few years older than Ahitub, the son of Phinehas. All this indicates a period of about 50 years or more had passed since the Philistines captured the ark.

The Lord’s priest in Shiloh. Since Eli was so emphatically known and described as God’s priest at Shiloh in 1 Samuel 1–4, and since there is every reason to believe that Shiloh was no longer the location of the ark in Saul’s time (see 1 Samuel 22; 1 Chronicles 13:3–5), it is better to understand this phrase as referring to Eli, not Ahijah. The words that follow, "wearing an ephod," then apply to Ahijah (see 1 Samuel 2:28 and the note on Judges 1:1).