Matthew 19:4

He said, Have ye not read — So instead of contradicting him, our Lord confutes them by the very words of Moses. He who made them, made them male and female from the beginning — At least from the beginning of the Mosaic creation. And where do we read of any other? Does it not follow, that God's making Eve was part of his original design, and not a consequence of Adam's beginning to fall? By making them one man and one woman, he condemned polygamy: by making them one flesh, he condemned divorce.