Leviticus 16:2

16:2 and the Lord said to Moses: “Tell Aaron your brother that he must not enter at any time into the holy place inside the veil-canopy in front of the atonement plate that is on the ark so that he may not die, for I will appear in the cloud over the atonement plate.

Leviticus 16:15

16:15 “He must then slaughter the sin offering goat which is for the people. He is to bring its blood inside the veil-canopy, and he is to do with its blood just as he did to the blood of the bull: He is to sprinkle it on the atonement plate and in front of the atonement plate.

Leviticus 21:23

21:23 but he must not go into the veil-canopy or step forward to the altar because he has a physical flaw. Thus he must not profane my holy places, for I am the Lord who sanctifies them.’”