Numbers 1:44

These are those that were numbered, which Moses and Aaron numbered, and the princes of Israel, being twelve men: each one was for the house of his fathers.

Cross-reference

Numbers 1:2-16 provides the command and tribal leaders for the census, showing how the total in v.44 was conducted.

Numbers 26:64 reveals that none of the men counted in the first census entered Canaan, fulfilling God's judgment.