Verse 17 continues to quote from words of God in the Old Testament, Isa 52.11 (6.17abc) and Ezek 20.34, 41 in the Septuagint (6.17d). Since the quotation does not continue from the same place in the Old Testament as the quotation in verse 16, God’s New Covenant adds the words “as we also find in scripture” at the beginning of verse 17. By transposing the words inserted by Paul, “And so the Lord says,” Good News Translation likewise indicates that the quotation in verse 17 does not follow directly the quotation in verse 16. Paul also adds the logical connector Therefore, which is not found in the Old Testament text but is important to the New Testament argument. In Paul’s thinking it is because of what he cited in verse 16 that the appeal of verse 17 can be made. The Good News Translation rendering seems weak. One may prefer to translate “Therefore the Lord also says….”
In the Old Testament context the Israelite people are called upon to leave the city of Babylon, where they have been living in captivity. As Paul applies these quotations to the church, believers are to separate themselves from the immoral behavior and influence of nonbelievers (from them). In some languages it will be necessary to render the pronoun explicitly as “those who do not believe.”
The Lord in this verse is clearly “the Lord God” and not “the Lord Jesus.”
Unclean had a cultic sense in the passage from Isaiah, “not fit for use in worship.” For Paul the word unclean has primarily an ethical sense, “dirty because of sin.”
Then I will welcome you: God’s acceptance of his people depends upon their becoming separate from unbelievers. Revised Standard Version expresses this connection with the word then. Similarly New Jerusalem Bible and Moffatt. In the Septuagint text of Ezek 20.34, 41, God’s promise to welcome his people refers to welcoming or receiving them back from exile to the land that he had given them. For Paul, the meaning is that God will “accept” his people.
Quoted with permission from Omanson, Roger L. and Ellingworth, Paul. A Handbook on Paul’s Second Letter to the Corinthians. (UBS Handbook Series). New York: UBS, 1993. For this and other handbooks for translators see here .