Urim and Thummim
Archimandrite Nikifor’s Biblical Encyclopedia
(Exod. 28:30)—sacred objects or means of priestly inquiry placed in connection with the high priest’s breastpiece of judgment. Their Hebrew names have traditionally been associated with “lights” and “perfections,” but their exact form and etymology are uncertain. Scripture distinguishes them verbally from the twelve engraved stones of the breastpiece without describing their manufacture or appearance.