Numbers 18:14-16

ASV_Strongs(i)
  14 H2764 Everything devoted H3478 in Israel shall be thine.
  15 H6363 Everything that openeth H7358 the womb, H1320 of all flesh H7126 which they offer H3068 unto Jehovah, H120 both of man H929 and beast H1060 shall be thine: nevertheless the first-born H120 of man H6299 shalt thou surely H6299 redeem, H1060 and the firstling H2931 of unclean H929 beasts H6299 shalt thou redeem.
  16 H6299 And those that are to be redeemed H2320 of them from a month H1121 old H6299 shalt thou redeem, H6187 according to thine estimation, H3701 for the money H2568 of five H8255 shekels, H8255 after the shekel H6944 of the sanctuary H6242 (the same is twenty H1626 gerahs).