In commenting upon Matthew 19:6 from today’s Mass Readings, Saint John Chrysostom writes:
“Then he showed that it is a fearful thing to tamper with this law. When establishing this law, he did not say, “Therefore, do not sever or separate” but “What God has joined together, let man not separate.” If you quote Moses, I will quote the God of Moses, and with him I am always strong. For God from the beginning made them male and female. This law is very old, even if it appears human beings have recently discovered it. It is firmly fixed. And God did not simply bring the woman to her husband but ordered her also to leave her father and mother. And he not only ordered the man to go to the woman but also to cling to her, showing by his way of speaking that they could not be separated. And not even with this was God satisfied, but he sought also for another greater union: “for the two shall be one flesh (The Gospel of Matthew, Homily 54).”