Bamidbar 3:4-6

Orthodox Jewish Bible

⁴ And Nadav and Avihu died before Hashem, when they offered eish zarah (unauthorized fire) before Hashem, in the midbar of Sinai, and they had no children; and Eleazar and Itamar ministered in the kohen’s office in the sight of Aharon their av [Vayikra 10].

⁵ And Hashem spoke unto Moshe, saying,

⁶ Bring the tribe of Levi near [i.e., present them as offerings are presented], and present them before Aharon HaKohen, that they may minister unto him [i.e., help, be of service to him].