“and Aaron shall offer the Levites before Yahweh for a wave offering on the behalf of the children of Israel, that it may be theirs to do the service of Yahweh.”
Numbers 8:11 (WEB)
Context Reading
9You shall present the Levites before the Tent of Meeting. You shall assemble the whole congregation of the children of Israel. 10You shall present the Levites before Yahweh. The children of Israel shall lay their hands on the Levites, 11and Aaron shall offer the Levites before Yahweh for a wave offering on the behalf of the children of Israel, that it may be theirs to do the service of Yahweh. 12“The Levites shall lay their hands on the heads of the bulls, and you shall offer the one for a sin offering and the other for a burnt offering to Yahweh, to make atonement for the Levites. 13You shall set the Levites before Aaron and before his sons, and offer them as a wave offering to Yahweh.