Matthew 19:4-5, 8

And He answered and said to them, “Have you not read that He who made them at the beginning ‘made them male and female,’ 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’?

He said to them, “Moses, because of the hardness of your hearts, permitted you to divorce your wives, but from the beginning it was not so.