Numbers 26:4

Take the sum of the people, from twenty years old and upward; as the Lord commanded Moses and the children of Israel, which went forth out of the land of Egypt.

Cross-reference

Numbers 1:1 begins the first census in Sinai; Numbers 26:4 repeats the command for a new generation in Moab.

1 Chronicles 21:1 shows Satan inciting David to take a census — contrasting with God's commanded census here.