1 Corinthians 5:9, Not to Company With Fornicators
The psalmist echo the words of the Apostle Paul in Psalm 1:1 Blessed is the man that walketh not in the counsel of the ungodly, nor standeth in the way of sinners, nor sitteth in the seat of the scornful.
He tells them that he has written to them in a previous letter to have no association with that particular man who committed incest. The word “fornicator” comes from the verb “to sell” which is from the verb “to pass through or carry over” (particularly as merchants) and thence to sell, describing a whoremonger or male prostitute.He tells them to be careful of immoral people, do not keep close company with them (MacArthur).