Verse 4 expresses the reason that Paul is sending these brothers on ahead to Corinth (verse 3). He wanted to determine whether they were really prepared, in order to avoid mutual embarrassment.

Lest: while Revised Standard Version and certain other versions follow the Greek in continuing the sentence started at the beginning of verse 3, it will be better in most languages to start a new sentence here with a word like “Otherwise” (Bible en français courant) or “However” (Good News Translation).

To whom do the words some Macedonians refer? The Greek is literally “Macedonians.” By adding the definite article “the” before the word “people,” Good News Translation suggests a specific group of people. It seems that after sending Titus and the two unnamed brothers, Paul himself will go to Corinth and may take with him some Christians from the province of Macedonia. The translations some (Revised Standard Version, New Revised Standard Version, New Jerusalem Bible) people from Macedonia or “if any Macedonians” (New American Bible, New International Version) are preferable to “the people from Macedonia” (Good News Translation), since Paul does not appear to be referring to a specific group of people. The Revised English Bible translation, “men from Macedonia,” is more specific than the Greek requires; women may have been included also.

Paul was concerned that the Corinthians may not be ready, that is, that they may not have their part of the contribution ready (see 1 Cor 16.1-2). Contemporary English Version says “I want them to find that you have the money ready.”

The context clearly shows that the we in this case excludes the Corinthian readers, since it contrasts with you later in the same sentence.

Be humiliated: in those languages where passive expressions are problematic, it will be necessary to indicate who the agent is in the process of humiliation. In this case it is clearly the Corinthians if they are unprepared for the offering. One may say more directly “you will cause us to feel shame.” But in some languages it will be possible to say simply “we will feel shame.”

To say nothing of you: literally “lest I say you.” This rather cryptic parenthetical statement may have to be translated in some languages as a separate sentence at the end of the verse. One may say “I won’t even mention the shame you might feel.”

For being so confident: it is doubtful whether the meaning “confidence” can be established for the Greek word translated as confident in Revised Standard Version. Good News Translation and most other English versions, however, follow the same meaning as Revised Standard Version. The Greek word is better translated as “plan,” “project,” or “undertaking.” The end of this verse should therefore be translated as “we would be humiliated—to say nothing of you—in this undertaking” (New Revised Standard Version and Anchor Bible).

At the end of this verse, some manuscripts add the words “of this boasting” (so REB footnote). The UBS Greek New Testament does not include these words, and the editors give a “B” evaluation to the printed text, suggesting that the printed text is almost certainly correct. King James Version is based on the manuscripts that have this addition: “should be ashamed in this same confident boasting.” With the additional words the sense is clearly that Paul would be humiliated for having confidently boasted about the Corinthians (see 7.14 and 9.3). Some translations such as Revised Standard Version and Good News Translation have followed manuscripts that do not have these additional words; but the translators understand the sense to be the same, even without the addition.

As already stated, however, the Greek word translated confident in Revised Standard Version is more accurately translated “undertaking.” The humiliation that Paul fears is not that he may have boasted in vain. Rather he will be humiliated if the undertaking of the fund-raising for the Christians in Jerusalem should fail. The following translation may serve as a model for this verse:
• However, if some people from Macedonia should come with me to Corinth and find out that you are not ready, how ashamed we [exclusive] would be if this project of collecting money should fail. And I will not even talk about your shame in this matter.

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 .