Why did Paul tell the Corinthians they didn't have to worry about handing their offering over to Titus and the men coming?

Les explains that Paul was reassuring the Corinthians about the men coming, probably headed up by Titus. He calls them men of integrity, so the Corinthians did not have to worry about turning over their offering; those men would get every penny of it to Jerusalem where it was supposed to go. The ministering Paul refers to was to the poor saints in Jerusalem, who had been left destitute because of their offerings into the common kitty beginning with Acts chapter 2. Paul also boasts to the Macedonians about the Corinthians' zealousness in making these collections, and he sent the brethren so that boasting would not be in vain and they would be ready. Les suggests Paul is using a little psychology, building them up. He notes that Titus and the gentlemen were already making collections in the poorest mountainous part of Greece, and when they came to a cultural and commercial center like Corinth, more wealth would be available than in the mountains.