16 Again, objection has been taken to my comments on the apostle in the following passage: But lest any should suppose from the context of the words before quoted (namely, 'that you may give yourselves...to prayer and come together again') that the apostle desires this consummation, and does not merely concede it to obviate a worse downfall, he immediately adds, 'that Satan tempt you not for your incontinency.' 'And come together again.' What a noble indulgence the words convey!
One which he blushes to speak of in plainer words, which he prefers only to Satan's temptation, and which has its root in incontinence. Do we labor to expound this as a dark saying when the writer has himself explained his meaning? “I speak this,” he says, 'by way of permission, and not as a command.' Do we still hesitate to speak of wedlock as a thing permitted instead of as a thing enjoined? Or are we afraid that such permission will exclude second or third marriages or some other case?
What have I said here which the apostle has not said? The phrase, I suppose, “which he blushes to speak of in plainer words.” I imagine that when he says “come together,” and does not mention for what, he takes a modest way of indicating what he does not like to name openly— that is, sexual intercourse. Or is the objection to the words which follow— “which he prefers only to Satan's temptation, and which has its root in incontinence”? Are they not the very words of the apostle, only differently arranged— “that Satan tempt you not for your incontinency”?
Or do people cavil because I said, “Do we still hesitate to speak of wedlock as a thing permitted instead of as a thing enjoined?” If this seems a hard saying, it should be ascribed to the apostle, who says, “But I speak this by way of permission, and not as a command,” and not to me, who, except that I have rearranged their order, have changed neither the words nor their meaning.
Source: Letters (New Advent)