Matthew 19:5-8

And God said, ‘So a man will leave his father and mother and be united with his wife, and the two will become one body.’ So there are not two, but one. God has joined the two together, so no one should separate them.” The Pharisees asked, “Why then did Moses give a command for a man to divorce his wife by giving her divorce papers?” Jesus answered, “Moses allowed you to divorce your wives because you refused to accept God’s teaching, but divorce was not allowed in the beginning.