Some translations set quotations from the Old Testament farther to the right on the page than the rest of the text. The ULB does this with the quoted words of verse 15.
The church in Corinth started preparing to give money to the poor believers in Jerusalem. The churches in Macedonia also had given generously. Paul sends Titus and two other believers to Corinth to encourage the Corinthians to give generously. Paul and the others will carry the money to Jerusalem. They want people to know it is being done honestly.
A "paradox" is a true statement that appears to describe something impossible. These words in verse 2 are a paradox: "the abundance of their joy and the extremity of their poverty have produced great riches of generosity." In verse 3 Paul explains how their poverty produced riches. Paul also uses riches and poverty in other paradoxes. ([2 Corinthians 8:2](./01.md))