Charles Ellicott Commentary 1 Samuel 22:10

"And he inquired of Jehovah for him, and gave him victuals, and gave him the sword of Goliath the Philistine." — 1 Samuel 22:10 (ASV)

And he inquired of the Lord for him. — This is, however, by no means certain (see below); nothing was said about the Urim and Thummim being brought out and questioned by the high priest on the occasion of David’s visit. It is possible that Doeg was misled here by the fact of the high priest’s going into the sanctuary, where the ephod was, to fetch the sword of Goliath for David. This famous sword was laid up, we know, behind the ephod.