1 Samuel 23:6

And it came to pass, as is here noted in explanation, when Abiathar, the son of Ahimelech, fled to David to Keilah, joining him just when the campaign to rescue the city was planned, that he came down with an ephod, the shoulder-dress of the high priest with the Urim and Thummim, in his hand. This was in David's favor, for he could now at any time ask the will of the Lord.