Numbers 3:38-39

38Now those who were to 1camp before the tabernacle eastward, before the tent of meeting toward the sunrise, are Moses and Aaron and his sons, performing the duties of the sanctuary for the obligation of the sons of Israel; but 2the 3layman coming near was to be put to death. 39All the numbered men of the Levites, whom Moses and Aaron numbered at the 4command of the Lord by their families, every male from a month old and upward, were 522,000.