Bamidbar 8:17-19

Orthodox Jewish Bible

¹⁷ For Kol Bechor Bnei Yisroel are Mine, both adam and behemah; on the day that I struck down kol bechor in Eretz Mitzrayim I set them apart as kodesh for Myself.

¹⁸ And I have taken the Levi’im tachat (instead of) Kol Bechor Bnei Yisroel.

¹⁹ And I have given the Levi’im as a gift to Aharon and to his Banim from among the Bnei Yisroel, to do the Avodat Bnei Yisroel in the Ohel Mo’ed, and to make kapporah for the Bnei Yisroel; so that there be no plague among the Bnei Yisroel, when the Bnei Yisroel come near unto HaKodesh.