Paul's free preaching was being held against him. Barnes says his opponents clearly used it as an objection, as if Paul's refusal of support showed he knew he had no real claim to be an apostle. So Paul asks, with a touch of irony, whether lowering himself was a crime. The lowering was real: Barnes describes it as working with his own hands, "by submitting to voluntary poverty." Gill adds that because Paul took nothing, his preaching "could not be thought to be with any view to himself, and his own advantage." The question presses the Corinthians to see that the very thing they counted against him was done "that ye might be exalted."

Paul answers his own question by explaining what he did. "I robbed other churches, taking wages of them, to do you service" (2 Corinthians 11:8). When he was in need at Corinth, "the brethren which came from Macedonia supplied" (2 Corinthians 11:9). He will not change course: "so will I keep myself" (2 Corinthians 11:9), and "no man shall stop me of this boasting in the regions of Achaia" (2 Corinthians 11:10). The implied answer is no. It was no sin to serve them freely.

When Paul first came to Corinth he stayed with Aquila and Priscilla and worked with them, "for by their occupation they were tentmakers" (Acts 18:1-3). Matthew Henry says Paul "chose rather to abase himself, by working with his hands in the trade of tent-making." The Greek behind "committed an offence" is hamartian epoiesa, literally "did I commit a sin," as Barnes also notes. "Freely" translates dorean, meaning without charge. Barnes thinks the "other churches" of 2 Corinthians 11:8 probably refers especially to the Philippians, who "sent once and again unto my necessity" (Philippians 4:15-16).

Paul's question turns the usual measure of greatness upside down. His rivals treated his refusal of pay as proof that he was no real apostle. Paul chose to be lowered so that others could be lifted, and he calls what he gave away "the gospel of God" (2 Corinthians 11:7). Barnes points back to 1 Corinthians 9, where Paul says he had every right to support, since "the Lord ordained that they which preach the gospel should live of the gospel" (1 Corinthians 9:14). Yet he set that right aside "lest we should hinder the gospel of Christ" (1 Corinthians 9:12).

The question also shows how easily good can be misread. Paul does not stop serving freely because it is misunderstood. He explains himself plainly and keeps going (2 Corinthians 11:9-12).