The Gospel According to St. Matthew
Matthew Chapter 19:
Ver.7 - 9. "They say unto him, Why did Moses then command to give a writing of divorcement, and to put her away? He saith unto them, Moses because of the hardness of your hearts suffered you to put away your wives: but from the beginning it was not so. And I say unto you, Whosoever shall put away his wife, except it be for fornication, and shall marry another, committeth adultery: and whoso marrieth her which is put away doth commit adultery."
When the Pharisees saw that the Lord had confuted them, they were compelled to bring forward Moses as a lawgiver who contradicted Christ,and they asked " Why did Moses then command to give a writing of divorcement, and to put her away?" Then the Lord, turning every accusation upon their own head, defends Moses by saying, "Moses did not set this law in contradiction to God, but rather he addressed this law to your depravity, so that when you in your licentiousness desired to come together with other women, you would not put to death your first wife." For the Israelites, being cruel, would have murdered their wives if they were constrained to keep them. So, Moses provided in the law for a writ of divorce to be given to those wives who were hated by their husbands. But I say unto you, Christ says, that it is good to divorce as an adulteress a wife who has committed fornication, but if one divorces a wife who has not committed fornication, he becomes in part the cause of adultery for her if she should marry again. Understand this also, that "he that is joined unto the Lord is of one spirit with Him" and a union takes place between the believer and Christ. For we have all become one body with Him and we are, each one of us, members of Christ. So indeed no one can separate from such a union, as Paul said, Who can separate us from the love of Christ? For what God had joined together nothing can separate, as Paul says, neither man nor any other created thing, not angels, principalities, or powers.
Ver. 10. "His disciples say unto Him, If the case of the man be so with his wife, it is not good to marry."
The disciples are troubled and say, "If they are joined together so that they are one and remain inseparable their whole life, so that even if the wife should be a schemer, or worse, he dare not divorce her, it is not expedient to marry. For it would be easier not to marry, and to war and struggle against physical desires, than to endure a wicked woman. "The case of the man with his wife" means the unbreakable union. But some interpret it this way: if the case of man be so, that is, if the man who unlawfully divorces his wife draws such a charge, or blame and accusation, against himself, it is not expedient to marry.
THE EXPLANATION BY BLESSED THEOPHYLACT OF THE HOLY GOSPEL ACCORDING TO ST. MATTHEW, pg. 162-163