Leviticus 10:6

10:6 Then Moses said to Aaron and to Eleazar and Ithamar his other two sons, “Do not dishevel the hair of your heads and do not tear your garments, so that you do not die and so that wrath does not come on the whole congregation. Your brothers, all the house of Israel, are to mourn the burning which the Lord has caused,

Leviticus 11:32

11:32 Also, anything they fall on when they die will become unclean – any wood vessel or garment or article of leather or sackcloth. Any such vessel with which work is done must be immersed in water and will be unclean until the evening. Then it will become clean.

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.