Heidegger's Bible Handbook: 1 Corinthians: Another Corinthian Epistle?

6. Whether another Epistle of Paul to the Corinthians preceded this one?

That Saint Paul wrote another Epistle to the Corinthians prior to this, both the ancients, and some more recent men, among whom are also Louis Cappel, Lightfoot, and Grotius, gather out of 1 Corinthians 5:9-11, where he says that he wrote in an Epistle, not to company with fornicators:but now he wrote, etc.But Chrysostom looses the argument, asserting that the Apostle has regard to verses 2 and 7 of this very chapter.Neither does that νυνὶδὲ, but now, hinder:since it is not always a note of time, but sometimes of transition; which is to say, although I wrote to you, that fornicators are to be avoided, I did not understand Pagans, but Christians.Be that as it may, all Antiquity saw no other but these two, and never admitted any other.And these are abundantly sufficient for our learning and instruction.