Matthew 19:7

4 And he answered and said, Have ye not read, that he who made [them] from the beginning made them male and female,

5 and said, For this cause shall a man leave his father and mother, and shall cleave to his wife; and the two shall become one flesh?

6 So that they are no more two, but one flesh. What therefore God hath joined together, let not man put asunder.

7 They say unto him, Why then did Moses command to give a bill of divorcement, and to put [her] away?

8 He saith unto them, Moses for your hardness of heart suffered you to put away your wives: but from the beginning it hath not been so.

9 And I say unto you, Whosoever shall put away his wife, except for fornication, and shall marry another, committeth adultery: and he that marrieth her when she is put away committeth adultery.

10 The disciples say unto him, If the case of the man is so with his wife, it is not expedient to marry.