Numbers 26:57-62

57These were the Levites who were counted by their clans: through Gershon, the Gershonite clan; through Kohath, the Kohathite clan; through Merari, the Merarite clan.

58These also were Levite clans: the Libnite clan, the Hebronite clan, the Mahlite clan, the Mushite clan, the Korahite clan. (Kohath was the forefather of Amram; 59the name of Amram’s wife was Jochebed, a descendant of Levi, who was born to the Levites Or Jochebed, a daughter of Levi, who was born to Levi in Egypt. To Amram she bore Aaron, Moses and their sister Miriam. 60Aaron was the father of Nadab and Abihu, Eleazar and Ithamar.

61But Nadab and Abihu died when they made an offering before the LORD with unauthorized fire.)

62All the male Levites a month old or more numbered 23,000. They were not counted along with the other Israelites because they received no inheritance among them.