Vayikra (Leviticus): Shemini > Ch 10
Aaron’s sons Nadab and Abihu bring a wrong offering, and are consumed by G-d’s fire
Aaron's sons, Nadab and Abihu, each took his pan, put fire in them, placed incense upon it, and they brought before the Lord foreign fire, which He had not commanded them. And fire went forth from before the Lord and consumed them, and they died before the Lord.
Then Moses said to Aaron, "This is what the Lord spoke, [when He said], 'I will be sanctified through those near to Me, and before all the people I will be glorified.' " Aaron was silent. Moses asked Mishael and Elzaphan, the sons of Aaron's uncle Uzziel, to take the bodies to the outside of the camp.
Moses said to Aaron and to Eleazar and to Ithamar, his sons, "Do not leave your heads unshorn, and do not rend your garments, so that you shall not die, and lest He be angry with the entire community, but your brothers, the entire house of Israel, shall bewail the conflagration that the Lord has burned. And do not go out of the entrance of the Tent of Meeting, lest you die, because the Lord's anointing oil is upon you." And they did according to Moses' order.
G-d commands Aaron & the kohanim to always be sober in the Tent of the Meeting
G-d told Aaron:
Do not drink wine that will lead to intoxication, neither you nor your sons with you, when you go into the Tent of Meeting, so that you shall not die. [This is] an eternal statute for your generations, to distinguish between holy and profane and between unclean and clean, and to instruct the children of Israel regarding all the statutes which the Lord has spoken to them through Moses.
Moses agrees with Aaron & his sons when they don’t eat from the sin offering due to their grief
Moses told Aaron & his surviving sons, Eleazar and Ithamar to eat from the meal offering. He also reminded them that the breast of the waving and the thigh of the raising up will always belong to them
Moses investigated and found that the sin offering goat, had been burnt but not eaten by the kohanim. He demanded an explanation. Aaron said: "But today, did they offer up their sin offering and their burnt offering before the Lord? But [if tragic events] like these had befallen me, and if I had eaten a sin offering today, would it have pleased the Lord?" Moses heard [this], and it pleased him.
Research & Analysis
Nadab and Abihu
The wrath of G-d is upon all who presume to worship Him in a manner He has not commanded, in a manner that could be disrespectful.