Mark 10:2-9

The Pharisees came and asked Him, “Is it lawful for a man to divorce his wife?” testing Him. And He answered and said to them, “What did Moses command you?” They said, “Moses permitted a man to write a certificate of divorce, and to dismiss her.” And Jesus answered and said to them, “Because of the hardness of your heart he wrote you this precept. But from the beginning of the creation, God ‘made them male and female.’ ‘For this reason a man shall leave his father and mother and be joined to his wife, and the two shall become one flesh’; so then they are no longer two, but one flesh. Therefore what God has joined together, let not man separate.”