Exodus 28:29–30

29 “Whenever he enters the sanctuary, Aaron is to carry the names of Israel’s sons over his heart on the breastpiece for decisions, as a continual reminder before the Lord. 30 Place the Urim and Thummima in the breastpiece for decisions, so that they will also be over Aaron’s heart whenever he comes before the Lord. Aaron will continually carry the means of decisions for the Israelites over his heart before the Lord.