The Orem and the Thumimim

The e-fod is the high priest's robe with golden bells attached to it. Between each bell there was a pomegranate, Exodus 28, 34, and Exodus 39, 26. You don't actually see this in the Old Testament, but there are rabbinic speculations about why the bells were there or what purpose they served. And you'll read of speculations like when the high priest, especially at the day of Atonement, stood before the Ark of the Covenant,. He entered the most holy place.