1 Samuel 23:6

He came down with an ephod Rather, with the ephod, namely, the high-priest's ephod, wherein were the Urim and Thummim. For Abiathar, being left, it is probable, to keep the sanctuary, while his father Ahimelech and the rest of the priests went to wait upon Saul, as soon as he heard of their slaughter he took this principal vestment of the high-priest, and carried it to David. Thus God, in the course of his providence, gave him an opportunity, while Doeg, the butcher, was killing his brethren, both of escaping himself and of bringing to David the ephod, of which now Saul was justly deprived.