1 Samuel 22:11
Then the king sent to call Ahimelech the priest, the son of Ahitub, and all his father’s house, the priests that were in Nob: and they came all of them to the king. Then the king sent to call Ahimelech the priest, the son of Ahitub, and all his father’s house, the priests that were in Nob: and they came all of them to the king.
The summons recorded in the verse came in maddened rage after David escaped the trap Saul had planned for him at the cave of Adullam, when the king called Ahimelech the son of Ahitub and all his father's house, the priests that were in Nob, to come all of them before him. Saul acted because he believed traitors in his own camp had warned David of his designs. He therefore charged his counselors with conspiracy against him and offered rich gifts and positions of honor to discover who had befriended David.
His anger against the man of God was kindled by Doeg the Edomite, who reported David's visit to Ahimelech in a false light. Doeg was moved by ambition and greed and by hatred of Ahimelech, who had reproved his sins, and by slander his hell-fired tongue stirred Saul's worst passions until Saul determined that the whole priestly family should perish. The summons was the first step of that terrible decree of death, which was executed by Doeg's murderous hand and brought ruin upon Nob. The episode reveals the perversity of a heart that refuses God's guidance and acts under Satan's control, for from false compassion Saul had spared the Amalekites devoted to destruction despite God's command for their utter destruction, yet now without any command from God he slew the priests of the Lord.