It is reported commonly that there is fornication among you, and such fornication as is not so much as named among the Gentiles, that one should have his father's wife. There is fornication among you - The word πορνεια, which we translate fornication in this place, must be understood in its utmost latitude of meaning, as implying all kinds of impurity; for, that the Corinthians were notoriously guilty of every species of irregularity and debauch, we have already seen; and it is not likely that in speaking on this subject, in reference to a people so very notorious, he would refer to only one species of impurity, and that not the most flagitious.
That one should have his father's wife - Commentators and critics have found great difficulties in this statement. One part of the case is sufficiently clear, that a man who professed Christianity had illegal connections with his father's wife; but the principal question is, was his father alive or dead? Most think that the father was alive, and imagine that to this the apostle refers, 2 Corinthians 7:12, where, speaking of the person who did the wrong, he introduces also him who had suffered the wrong; which must mean the father and the father then alive. After all that has been said on this subject, I think it most natural to conclude that the person in question had married the wife of his deceased father, not his own mother, but stepmother, then a widow.
This was a crime which the text says was not so much as named among the Gentiles; the apostle must only mean that it was not accredited by them, for it certainly did often occur: but by their best writers who notice it, it was branded as superlatively infamous. Cicero styles it, scelus incredibile et inauditum, an incredible and unheard of wickedness; but it was heard of and practised; and there are several stories of this kind in heathen authors, but they reprobate not commend it. The word ονομαζεται, named, is wanting in almost every MS. and version of importance, and certainly makes no part of the text. The words should be read, and such fornication as is not amongst the Gentiles, i.e., not allowed. Some think that this woman might have been a proselyte to the Jewish religion from heathenism; and the rabbins taught that proselytism annulled all former relationship, and that a woman was at liberty in such a case to depart from an unbelieving husband, and to marry even with a believing son, i.e., of her husband by some former wife.