Ephesians 5:3

But fornication, and all uncleanness, or covetousness
The apostle proceeds to dehort from several vices, which are unbecoming the dear children and followers of God; and which the love of Christ should constrain them to avoid: the first of these, which is simple "fornication", is the sin which is committed between single or unmarried persons; and is contrary to the law of God, is a work of the flesh, and is against a man's own body; it renders persons unfit for church communion, brings many temporal calamities upon them, and exposes them to divine wrath, and excludes from the kingdom of heaven, without repentance; and the reason why it is so often taken notice of is, because it was very frequent among the Gentiles, and not thought criminal: "all uncleanness" takes in adultery, incest, sodomy, and every unnatural lust; and "covetousness" seems not so much to design that sin which is commonly so called, namely, an immoderate desire after worldly things, as a greedy and insatiable appetite after the above lusts:

let it not be once named among you,
as becometh saints; that is, neither one or other of them; the sense is, that they should not be committed; so that there might be no occasion to speak of them, even though with abhorrence, as if there were no such vices in being; and much less should they be named with pleasure, and pleaded for: for thus it becomes such who are set apart by God the Father, whose sins are expiated by the blood of Christ, and whose hearts are sanctified by the Spirit of God; who profess the Gospel of Christ, and have a place and a name in God's house, better than that of sons and daughters.