Exodus 28:29
And Aaron shall bear the names of the children of Israel in the breastplate of judgment on his heart, when he goes in to the holy place, for a memorial before the LORD continually.
Torrey's Topical Textbook—AKJV

Leviticus 16:2,3
And the LORD said to Moses, Speak to Aaron your brother, that he come not at all times into the holy place within the veil before the mercy seat, which is on the ark; that he die not: for I will appear in the cloud on the mercy seat.
Torrey's Topical Textbook—AKJV