Urim and Thummim
The Urim (Hebrew: אוּרִים ʾŪrīm, "lights") and the Thummim (Hebrew: תֻּמִּים Tummīm, "perfection" or "truth") in the Hebrew Bible are elements of the hoshen, the breastplate worn by the High Priest attached to the ephod, a type of apron or garment. The pair are used frequently in the Old Testament, in Exodus 28:30 and Leviticus 8:8 through God's instruction to Aaron on how to adorn his breastplate worn in the holy place; in 1 Samuel 14:41 by King Saul to determine who was at fault for breaking the army's fast; and Ezra 2 to determine whether those who claimed to be the descendants of the priests of Israel were truly of that class.