1 Samuel 23:7-9

And it was told Saul that David was come to Keilah. And Saul said, God hath delivered him into mine hand; for he is shut in, by entering into a town that hath gates and bars. And Saul called all the people together to war, to go down to Keilah, to besiege David and his men. And David knew that Saul secretly practised mischief against him; and he said to Abiathar the priest, Bring hither the ephod.