4 For if any Macedonians come with me and find you unprepared, we—not to say anything about you—would be ashamed of having been so confident.

Read 2 Corinthians 9:4 Using Other Translations

Lest haply if they of Macedonia come with me, and find you unprepared, we (that we say not, ye) should be ashamed in this same confident boasting.
Otherwise, if some Macedonians come with me and find that you are not ready, we would be humiliated--to say nothing of you--for being so confident.
We would be embarrassed—not to mention your own embarrassment—if some Macedonian believers came with me and found that you weren’t ready after all I had told them!