4 Take the sum of the people, from twenty years old and upward; as the LORD commanded Moses and the children of Israel, who went forth from the land of Egypt.
Numbers 26:4 Cross References - Webster
Numbers 1:1
1 And the LORD spoke to Moses in the wilderness of Sinai, in the tabernacle of the congregation, on the first day of the second month, in the second year after they had come out of the land of Egypt, saying,
1 Chronicles 21:1
1 And Satan stood up against Israel, and incited David to number Israel.