Mark 6:18

For John had said unto Herod, It is not lawful for thee to have thy brother’s wife.
— Mark 6:18, King James Version

In other translations

World English Bible (WEB)

For John said to Herod, "It is not lawful for you to have your brother's wife."

American Standard Version (ASV)

For John said unto Herod, It is not lawful for thee to have thy brother’s wife.

Young's Literal Translation (YLT)

for John said to Herod--'It is not lawful to thee to have the wife of thy brother;'