Commentary on the Gospel of Matthew

But, even if we have seemed to touch on things too deep for our capacity in the passages, nevertheless, because of the literal expression these things must further be said, that some of the laws were written not as excellent, but as by way of accommodation to the weakness of those to whom the law was given; for something of this kind is indicated in the words, “Moses for your hardness of heart suffered you to put away your wives;” but that which is pre-eminent and superior to the law, which was written for their hardness of heart, is indicated in this, “But from the beginning it has not been so.”

But in the new covenant also there are some legal injunctions of the same order as, “Moses for your hardness of heart suffered you to put away your wives;” for example, because of our hardness of heart, it has been written on account of our weakness, “But because of fornications, let each man have his own wife and let each woman have her own husband;” and this, “Let the husband render unto the wife her due, and likewise also the wife unto the husband.” To these sayings it is accordingly subjoined, “But this I say by way of permission, not of commandment.” But this also, “A wife is bound for so long time as her husband lives, but if her husband be dead, she is free to be married to whom she will, only in the Lord,” was said by Paul in view of our hardness of heart and weakness, to those who do not wish to desire earnestly the greater gifts and become more blessed.

But now contrary to what was written, some even of the rulers of the church have permitted a woman to marry, even when her husband was living, doing contrary to what was written, where it is said, “A wife is bound for so long time as her husband lives,” and “So then if while her husband lives, she shall be joined to another man she shall be called an adulteress,” not indeed altogether without reason, for it is probable this concession was permitted in comparison with worse things, contrary to what was from the beginning ordained by law, and written.