Matthew 19:4-6

And He answered and said to them, “Have you not read that He who [a]made them at the beginning ‘made them male and female,’ 5 and said, ‘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.”