Numbers 1:2-5

²Take the sum of all the congregation of the children of Israel by their families, and houses, and the names of every one, as many as are of the male sex,

³From twenty years old and upwards, of all the men of Israel fit for war, and you shall number them by their troops, thou and Aaron.

⁴And there shall be with you the princes of the tribes, and of the houses in their kindreds,

⁵Whose names are these: Of Ruben, Elisur the son of Sedeur.