Paul wrote First and Second Corinthians while ministering at Ephesus
Solution:
Letters of Paul or the epistles of Paul are the set of 13 books of New Testament that are attributed to Saint Paul also named as Paul the Apostle and Sosthenes, the co-author.
The 1 Corinthians 5:9 is "I wrote to you in my letter not to associate with sexually immoral persons."
It was while staying in Ephesus, Paul composed both the First and Second Corinthians from his second year at Ephesus.
Lying on the coasts of Ionia, Ephesus is one of the ancient Greek city which was built in 10th century BC.