Heidegger's Bible Handbook: 1 Corinthians: Time of Writing

5. The time of the writing of the same is investigated.

That this Epistle was written at Ephesus, we have argued above. That is, the Corinthians wrote to him there, 1 Corinthians 7:1, and that, as it appears, through Stephanas and Fortunatus, whom they had sent to him, 1 Corinthians 16:17, through whom Paul appears likewise to have written back this Epistle in reply, since in it he greatly commends them to the Corinthians, 1 Corinthians 16:15-18. Moreover, it appears to have been written at Ephesus, a little before, departing thence, he proceeded to Macedonia, even indeed about the end of those three years that he spent at Ephesus; which out of 1 Corinthians 16:1-3 and Acts 19:1 is readily gathered:more precisely a little before Pentecost. For in 1 Corinthians 16:8 he says, I will tarry at Ephesus until Pentecost.But this Pentecost preceded that Pentecost, on which he had determined to be at Jerusalem, Acts 20:16. Therefore, thus this Epistles also was written by Paul while he was yet free, to be bound approximately a year afterwards at Jerusalem, and so, according to the calculation of Ussher and other highly recommended men, in the fiftieth year after the birth of Christ.