Matthew 19:6-9

6So they are no longer two, but one flesh. Therefore what God has joined together, let no one separate.”

7“Why then,” they asked, “did Moses command that a man give his wife a certificate of divorce and send her away?” 8Jesus replied, “Moses permitted you to divorce your wives because your hearts were hard. But it was not this way from the beginning.

9I tell you that anyone who divorces his wife, except for sexual immorality, and marries another woman commits adultery.”