Mark 6:18 in the World English Bible
For John had said to Herod, “It is not lawful for you to have your brother’s wife.”
Context
17 For Herod himself had sent forth and laid hold upon John, and bound him in prison for Herodias’ sake, his brother Philip’s wife: for he had married her.
18 For John had said unto Herod, It is not lawful for thee to have thy brother’s wife.
19 Therefore Herodias had a quarrel against him, and would have killed him; but she could not: