Numbers 3:38-51

Now those to camp before the tabernacle toward the east, before the Tent of Meeting, toward the sunrise, were to be Moses, and Aaron and his sons, performing the duties of the sanctuary for whatever was required of the Israelites; and the layman (non-Levite) who approached [the sanctuary] was to be put to death. All the men of the Levites whom Moses and Aaron numbered at the command of the LORD, by their families, every male from a month old and upward, were 22,000. Then the LORD said to Moses, “Number every firstborn male of the Israelites from a month old and upward, and make a list of their names. You shall take the Levites for Me instead of and as a substitute for all the firstborn among the Israelites. I am the LORD; and you shall take the cattle of the Levites instead of and as a substitute for all the firstborn among the cattle of the Israelites.” So Moses numbered all the firstborn among the Israelites, just as the LORD had commanded him; and all the firstborn males from a month old and upward as numbered were 22,273 [273 more than the Levites]. Then the LORD spoke to Moses, saying, “Take the Levites [for Me] instead of all the firstborn among the sons of Israel, and the cattle of the Levites instead of their cattle. And the Levites shall be Mine. I am the LORD. For the ransom (redemption price) of the 273 of the firstborn of the Israelites who outnumber the Levites, you shall take five shekels apiece, per head, you shall take them in terms of the sanctuary shekel (the shekel is twenty gerahs), and give the money, the ransom (redemption price) of those who outnumber the Levites to Aaron and to his sons.” So Moses took the ransom (redemption) money from those who were in excess, beyond those ransomed by the Levites; from the firstborn of the Israelites he took the money in terms of the sanctuary shekel, 1,365 shekels. Then Moses gave the ransom money to Aaron and to his sons at the command of the LORD, just as the LORD had commanded Moses.