Leviticus 20:21

21 If a man takes his brother's wife, it is impurity; he has uncovered his brother's nakedness, they shall be childless.

Leviticus 20:21 In-Context

19 You shall not uncover the nakedness of your mother's sister or of your father's sister, for that is to make naked one's near kin; they shall bear their iniquity.
20 If a man lies with his uncle's wife, he has uncovered his uncle's nakedness; they shall bear their sin, they shall die childless.
21 If a man takes his brother's wife, it is impurity; he has uncovered his brother's nakedness, they shall be childless.
22 "You shall therefore keep all my statutes and all my ordinances, and do them; that the land where I am bringing you to dwell may not vomit you out.
23 And you shall not walk in the customs of the nation which I am casting out before you; for they did all these things, and therefore I abhorred them.
Revised Standard Version of the Bible, copyright 1952 [2nd edition, 1971] by the Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved.