Leviticus 10:1

English Standard Version

1 Now Nadab and Abihu, the sons of Aaron, each took his censer and put fire in it and laid incense on it and offered unauthorized[1] fire before the Lord, which he had not commanded them. (Ex6:23; Ex28:1; Ex30:9; Le16:1; Nu3:4; Nu16:18; Nu26:61; 1Ch24:2)

New International Version

1 Aaron’s sons Nadab and Abihu took their censers, put fire in them and added incense; and they offered unauthorized fire before the Lord, contrary to his command.

New Int. Readers Version

1 Nadab and Abihu were two of Aaron's sons. They got their shallow cups for burning incense. They put fire in them. They added incense to it. They made an offering to the Lord by using fire that wasn't allowed. They did it against his command.

King James Version

1 And Nadab and Abihu, the sons of Aaron, took either of them his censer, and put fire therein, and put incense thereon, and offered strange fire before the LORD, which he commanded them not.