Mark 10:3

And he arose from thence, and cometh into the coasts of Judaea by the farther side of Jordan: and the people resort unto him again; and, as he was wont, he taught them again.

And the Pharisees came to him, and asked him, Is it lawful for a man to put away his wife? tempting him.

And they said, Moses suffered to write a bill of divorcement, and to put her away.

And Jesus answered and said unto them, For the hardness of your heart he wrote you this precept.