Mark 10:9

6but from the beginning of the creation God made them a male and a female;

7on this account will a man leave his father and mother, and will cleave to his wife,

8and they will be—the two—for one flesh, so that they are no longer two, but one flesh;

9what God therefore joined together, do not let man separate.”

10And in the house His disciples again questioned Him of the same thing,

11and He says to them, “Whoever may put away his wife, and may marry another, commits adultery against her;

12and if a woman may put away her husband, and is married to another, she commits adultery.”