Numbers 3:14-18

Then the Lord spoke to Moses in the wilderness of Sinai, saying,

“Count the sons of Levi by their fathers’ households, by their families; every male from a month old and upward you shall count.”

So Moses counted them according to the word of the Lord, just as he had been commanded.

These, then, are the sons of Levi by their names: Gershon, Kohath, and Merari.

And these are the names of the sons of Gershon by their families: Libni and Shimei;