Verse 17 is a freely-worded quotation from Jer 9.24, the second time that Paul has quoted this verse in his letters to the Corinthians (see 1 Cor 1.31). The quotation marks in Revised Standard Version, New Revised Standard Version, and New American Bible indicate that Paul is quoting these words, without identifying the source. Other translations print this verse in italics to show that it is a quotation from scripture, and cite the source from Jeremiah in a note (Nueva Biblia Española, New Jerusalem Bible, Parola Del Signore: La Bibbia in Lingua Corrente). Good News Translation, Contemporary English Version, and Bible en français courant make explicit that Paul is quoting from the scripture by adding “as the scripture says” (see comments on 13.1). Parola Del Signore: La Bibbia in Lingua Corrente introduces the quotation by adding “The scripture says” and also uses italics for the quotation.

Boast of the Lord: New American Bible, New International Version, and New Revised Standard Version have “boast in the Lord.” Good News Translation correctly takes this to mean “about what the Lord has done.” The Lord in verses 17 and 18 is probably Christ rather than God, though either is possible (in the passage in Jeremiah itself, of course, “the Lord” is God), and the translator should leave the matter open. But if the language forces a decision, it will probably be better to say “the Lord Christ.”

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 .