Numbers 8:15 YLT

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.

¹⁶  'For they are certainly given to Me out of the midst of the sons of Israel, instead of him who openeth any womb -- the first-born of all -- from the sons of Israel I have taken them to Myself;

¹⁷  for Mine 'is' every first-born among the sons of Israel, among man and among beast; in the day of my smiting every first-born in the land of Egypt I sanctified them for Myself;