Numbers 8:13-15

Young's Literal Translation

¹³ and thou hast caused the Levites to stand before Aaron, and before his sons, and hast waved them -- a wave-offering to Jehovah;

¹⁴ and thou hast separated the Levites from the midst of the sons of Israel, and the Levites have become Mine;

¹⁵ and afterwards do the Levites come in to serve the tent of meeting, and thou hast cleansed them, and hast waved them -- a wave-offering.