Charles Ellicott Commentary 1 Samuel 2:28

"and did I choose him out of all the tribes of Israel to be my priest, to go up unto mine altar, to burn incense, to wear an ephod before me? and did I give unto the house of thy father all the offerings of the children of Israel made by fire?" — 1 Samuel 2:28 (ASV)

Did I choose him out of all the tribes of Israel? ... —After such glorious privileges had been conferred on this favored house, and such ample provision for all its wants had been made for it, it was indeed a crime of the blackest ingratitude that its leading members should pour dishonor on their invisible King and Benefactor.

To wear an ephod before me. —This included the privilege, which belonged to the head of the house of Aaron, the reigning high priest, of entering the Holy of Holies—that lightless inner sanctuary where the visible presence of the Eternal was from time to time pleased to dwell—and also the possession of the mysterious Urim and Thummim, by which inquiry could be made concerning the will of the invisible King of Israel.