Paul’s approach to being the missionary evangelist in Corinth was to rely on financial support from established churches elsewhere, rather than asking for money from the people he was trying to reach:
2 Corinthians 11:7-9 Was I wrong when I humbled myself and honored you by preaching God’s Good News to you without expecting anything in return? I ‘robbed’ other churches by accepting their contributions so I could serve you at no cost. And when I was with you and didn’t have enough to live on, I did not become a financial burden to anyone. For the brothers who came from Macedonia brought me all that I needed. I have never been a burden to you, and I never will be.
It means that Paul could never be accused of preaching the gospel to the Corinthians just to get rich. Why would he, anyway? His life was one of hardship because of that thorn in the flesh that kept him humble before God.
Any money he did accept was for others. In that, he suggested they give generously, even if only to keep a promise they’d made some time earlier.