Vayikra 10:1-3

Orthodox Jewish Bible

10 And Nadav and Avihu, the bnei Aharon, each took his censer, and put eish therein, and put ketoret (incense) thereon, and offered eish zarah (strange, unauthorized fire) before Hashem, which He commanded them not.

² And there went out eish (fire) from the presence of Hashem, and devoured them, and they died before Hashem.

³ Then Moshe said unto Aharon, This is it that Hashem spoke, saying, I will show Myself kadosh among them that come near Me, and before kol HaAm (all the People) I will be honored. And Aharon was silent.