Treasury of Scripture Knowledge
From twenty years old and upward, all that are able to go forth to war in Israel: you and Aaron shall number them by their armies.
But the Levites were not numbered among the children of Israel; as the LORD commanded Moses.
And these are they that were numbered of the Levites according to their families: of Gershon, the family of the Gershonites: of Kohath, the family of the Kohathites: of Merari, the family of the Merarites.
1 Chronicles 21:6
But Levi and Benjamin counted he not among them: for the king's command was abominable to Joab.