Matthew 19:6

3 And certain Pharisees came to him, testing him, and saying, Is it right for a man to put away his wife for every cause?

4 And he said in answer, Have you not seen in the Writings, that he who made them at the first made them male and female, and said,

5 For this cause will a man go away from his father and mother, and be joined to his wife; and the two will become one flesh?

6 So that they are no longer two, but one flesh. Then let not that which has been joined by God be parted by man.

7 They say to him, Why then did Moses give orders that a husband might give her a statement in writing and be free from her?

8 He says to them, Moses, because of your hard hearts, let you put away your wives: but it has not been so from the first.

9 And I say to you, Whoever puts away his wife for any other cause than the loss of her virtue, and takes another, is a false husband: and he who takes her as his wife when she is put away, is no true husband to her.