This verse is awkward and even meaningless when it is translated literally: “in order that as it is written, ‘Let he who boasts, boast in the Lord.’ ” As we suggested in the comments on verse 27, the Greek probably expresses result rather than purpose, like “so that” at the beginning of verse 29. An expanded restructuring would be “So now, as a result of all God has done for us in Christ [verse 29], we know what the scripture means when it says, ‘If anyone is going to boast, let him boast in the Lord.’ ” “In the Lord” probably means “of what the Lord has done” (Good News Bible), though the text in its Old Testament setting means literally “in God.”

For comments on it is written, see verse 19.

The previous verse has emphasized that God is the source of all that Christ has become for Christians, and of the Lord (Good News Bible “of what the Lord has done”) may mean “what God has done in Christ.” Similarly, the quotation may mean for Paul, “If anyone is going to boast, let it be about how God has changed him through Christ” (compare verse 30a).

In this verse, unlike verse 29, the word for boast has a good meaning. The corresponding Hebrew word appearing in Jer 9.24 is often used in praising God. In languages where it is necessary to use different expressions for (a) showing happiness openly with words, and (b) claiming to be superior to someone else, a translator should choose (a) here. In such cases it may be helpful to add a footnote that states that in Greek, the same verb is used in verse 29 and 31. In verse 31 the meaning that Paul gives to the Old Testament text is probably “Whoever wants to say why he is happy must say it is because Christ has made his life so much better than it was before.”

Quoted with permission from Ellingworth, Paul and Hatton, Howard A. A Handbook on Paul’s First Letter to the Corinthians, 2nd edition. (UBS Handbook Series). New York: UBS, 1985/1994. For this and other handbooks for translators see here .