Contradiction with Exodus 20:14
This verse states "Thou shalt not commit adultery," which contradicts Herod marrying his brother's wife as in Mark 6:17.
Exodus 20:14: Thou shalt not commit adultery.
Contradiction with Leviticus 18:16
This verse prohibits having relations with your brother's wife, which contrasts the action of Herod taking his brother Philip's wife in Mark 6:17.
Leviticus 18:16: Thou shalt not uncover the nakedness of thy brother's wife: it [is] thy brother's nakedness.
Contradiction with Leviticus 20:21
This verse declares that marrying your brother's wife is an impurity, opposing Herod's marriage to Herodias in Mark 6:17.
Leviticus 20:21: 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. [an...: Heb. a separation]
Contradiction with Matthew 14:4
John the Baptist condemns Herod's marriage to Herodias as unlawful, presenting a contradiction to the legitimacy implied in Mark 6:17.
Matthew 14:4: For John said unto him, It is not lawful for thee to have her.