Matthew 19:4-5, 8

And he answered and said unto them, Have ye not read, that he which made them at the beginning made them male and female, and said, For this cause shall a man leave father and mother, and shall cleave to his wife: and they twain shall be one flesh?

He saith unto them, Moses because of the hardness of your hearts suffered you to put away your wives: but from the beginning it was not so.