1 Samuel 23:2 - Ellicott's Commentary On The Whole Bible

David enquired of the Lord. — The enquiry was not made of the priest wearing the ephod, by means of the Urim and Thummim, for, according to 1 Samuel 23:6, Abiathar, the high priest who succeeded the murdered Ahimelech, only joined David at Keilah, the citizens of which place were then asking for his aid against their foes. But Gad the prophet was with David, and the enquiry was made, no doubt, through him. We know that such enquiries were made through prophets, for we possess a detailed account of such an enquiry being made by Jehoshaphat of the prophet Micaiah (1 Kings 22:5; 1 Kings 22:7-8), in which passage the same formula is used as in this case. The Talmud too, when discussing the enquiries made through the Urim and Thummim, whilst dwelling on the greater weight of the decision pronounced by the sacred stones, assumes that questions were also asked through the prophets. “The decree pronounced by a prophet is revocable, but the decision of the Urim and Thummim is irrevocable.” — Treatise Yoma, fol. 73 Colossians 1.