Numbers 8:10-12

Young's Literal Translation

¹⁰ and thou hast brought near the Levites before Jehovah, and the sons of Israel have laid their hands on the Levites,

¹¹ and Aaron hath waved the Levites -- a wave-offering before Jehovah, from the sons of Israel, and they have been -- for doing the service of Jehovah.

¹² `And the Levites lay their hands on the head of the bullocks, and make thou the one a sin-offering, and the one a burnt-offering to Jehovah, to atone for the Levites,