Numbers 3:5

2 And these are the names of the sons of Aaron: the first-born Nadab, and Abihu, Eleazar, and Ithamar;

3 these are the names of the sons of Aaron, the anointed priests, whose hand he hath consecrated for acting as priest.

4 And Nadab dieth--Abihu also--before Jehovah, in their bringing near strange fire before Jehovah, in the wilderness of Sinai, and sons they had not; and Eleazar--Ithamar also--acteth as priest in the presence of Aaron their father.

5 And Jehovah speaketh unto Moses, saying,

6 `Bring near the tribe of Levi, and thou hast caused it to stand before Aaron the priest, and they have served him,

7 and kept his charge, and the charge of all the company before the tent of meeting, to do the service of the tabernacle;

8 and they have kept all the vessels of the tent of meeting, and the charge of the sons of Israel, to do the service of the tabernacle;