Mark 6:17-18

17 For Herod had sent and seized John, and bound him in prison for the sake of Hero'di-as, his brother Philip's wife; because he had married her.
18 For John said to Herod, "It is not lawful for you to have your brother's wife."
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.