Leviticus 10:2-12

2 A fire flashed from the LORD and burned them, and they died in the presence of the LORD.
3 Moses said to Aaron, "This is exactly what the LORD said: 'I will show my holiness among those who come to me. I will show my glory to all the people.'" Aaron was speechless.
4 Moses called Mishael and Elzaphan, the sons of Aaron's uncle, Uzziel. He told them, "Come and take your relatives away from in front of the holy place. Take them outside the camp."
5 So they came and took them away to a place outside the camp, as Moses told them. The dead men were still in their linen robes.
6 Moses told Aaron and his sons Eleazar and Ithamar: "Do not mourn by leaving your hair uncombed or tearing your clothes. If you do, you will die and the LORD will become angry with the whole congregation. All the other Israelites may cry over the fire the LORD sent, but you may not.
7 You must not leave the entrance to the tent of meeting or else you, too, will die, because the LORD has anointed you with his oil." They obeyed Moses.
8 The LORD spoke to Aaron,
9 "You and your sons must not drink any wine or liquor when you go into the tent of meeting, or you will die. This is a permanent law for generations to come.
10 Teach them the difference between what is holy and what is unholy, what is clean and what is unclean.
11 Also teach the Israelites all the laws that I gave them through Moses."
12 Moses told Aaron and his surviving sons Eleazar and Ithamar, "Take the grain offering left over from the offering by fire to the LORD. Make unleavened bread, and eat it next to the altar because it is very holy.