What does Leviticus 20:21 say in the KJV?

And if a man shall take his brother’s wife, it is an unclean thing: he hath uncovered his brother’s nakedness; they shall be childless.

A law given to the Israelites regarding marriage.

King James Version (public domain)

Traditionally attributed to Moses · c. 13th century BC · The Pentateuch — Genesis, Exodus, Leviticus, Numbers, and Deuteronomy — is traditionally attributed to him

Context

19And thou shalt not uncover the nakedness of thy mother’s sister, nor of thy father’s sister: for he uncovereth his near kin: they shall bear their iniquity.

20And if a man shall lie with his uncle’s wife, he hath uncovered his uncle’s nakedness: they shall bear their sin; they shall die childless.

21And if a man shall take his brother’s wife, it is an unclean thing: he hath uncovered his brother’s nakedness; they shall be childless.

22Ye shall therefore keep all my statutes, and all my judgments, and do them: that the land, whither I bring you to dwell therein, spue you not out.

23And ye shall not walk in the manners of the nation, which I cast out before you: for they committed all these things, and therefore I abhorred them.