Mark 10:5-12

And Jesus answered and said unto them, For the hardness of your heart he wrote you this precept. But from the beginning of the creation God made them male and female. For this cause shall a man leave his father and mother, and cleave to his wife; and they twain shall be one flesh: so then they are no more twain, but one flesh. What therefore God hath joined together, let not man put asunder. And in the house his disciples asked him again of the same matter. And he saith unto them, Whosoever shall put away his wife, and marry another, committeth adultery against her. And if a woman shall put away her husband, and be married to another, she committeth adultery.