Everything that opens the womb of all flesh that they offer to Yahweh, both of man and animal, will be yours; nevertheless you must redeem, yes, redeem, the firstborn of man, and you must redeem the firstborn of unclean animals. Bible

“redeem, yes, redeem.” This is the figure of speech polyptoton, where the word “redeem” is repeated twice in the Hebrew text, but the two occurrences are inflected differently. The double use of “redeem” is for emphasis, which some translations express by saying something such as, “You shall surely redeem.” [For more on the use of polyptoton, and the translation of it, see commentary on Gen. 2:16].

Commentary for: Numbers 18:15