'Sons of Levi' in the Bible

And these were the sons of Levi, by their names; Gershon, and Kohath, and Merari.

Take the sum of the sons of Kohath from among the sons of Levi, after their families, by the house of their fathers;

And put fire in them, and put incense in them before the LORD to-morrow: and it shall be that the man whom the LORD doth choose, he shall be holy: ye take too much upon you, ye sons of Levi.

And Moses said to Korah, Hear, I pray you, ye sons of Levi:

And he hath brought thee near to him, and all thy brethren the sons of Levi with thee: and seek ye the priesthood also?