Old Testament readings use the Septuagint , the Scripture the apostles quoted. Masoretic numbering shown for reference.Learn why
LXX

Numbers 18:15

And every thing that opens the womb of all flesh, whatsoever they bring to the Lord, whether man or beast, shall be thine: only the first-born of men shall be surely redeemed, and thou shalt redeem the first-born of unclean cattle.

Read in other translations