Matthew 19:6-9 NIV

[6] So 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?” [8] Jesus replied, “Moses permitted you to divorce your wives because your hearts were hard. But it was not this way from the beginning. [9] I tell you that anyone who divorces his wife, except for sexual immorality, and marries another woman commits adultery.”