David ran away from King Saul in 1 Samuel 21
One possibility is this: At the time, Ahimelech was old/weak and his son Abiathar was assisting him so much that Jesus saw Abiathar functionally as the high priest.
David and his men were hungry and asked Ahimelech for bread. Ahimelech ran out of ordinary bread.1 Then David came to Nob, to Ahimelech the priest. Ahimelek trembled when he met him, and asked, “Why are you alone? Why is no one with you?”
When Saul found out, he killed the priests at Nob. 1 Samuel 22:6a So the priest gave him the holy bread, for there was no bread there but the bread of the Presence
In the NT, Jesus spoke to the Pharisees in Mark 2:20But one of the sons of Ahimelech the son of Ahitub, named Abiathar, escaped and fled after David. 21And Abiathar told David that Saul had killed the priests of the LORD. 22And David said to Abiathar, “I knew on that day, when Doeg the Edomite was there, that he would surely tell Saul. I have occasioned the death of all the persons of your father’s house. 23Stay with me; do not be afraid, for he who seeks my life seeks your life. With me you shall be in safekeeping.”
But the OT recorded Ahimelech as the one who gave David the bread.25b “Have you never read what David did, when he was in need and was hungry, he and those who were with him: 26how he entered the house of God, in the time of Abiathar the high priest,
Who was the high priest when David ate the holy bread? How do we reconcile these passages?and ate the bread of the Presence, which it is not lawful for any but the priests to eat, and also gave it to those who were with him?”
One possibility is this: At the time, Ahimelech was old/weak and his son Abiathar was assisting him so much that Jesus saw Abiathar functionally as the high priest.