1 Now concerning the ministering to the saints, it is superfluous for me to write to you;
2 for I know your willingness, about which I boast of you to the Macedonians, that Achaia was ready a year ago; and your zeal has stirred up the majority.
3 Yet I have sent the brethren, lest our boasting of you should be in vain in this respect, that, as I said, you may be ready;
4 lest if some Macedonians come with me and find you unprepared, we (not to mention you!) should be ashamed of this confident boasting
5 Therefore I thought it necessary to exhort the brethren to go to you ahead of time, and prepare your generous gift beforehand, which you had previously promised, that it may be ready as a matter of generosity and not as a grudging obligation.
What! Must we belabour this subject still further? Hasn’t the apostle said quite enough about it by now? Yea, and he acknowledges: “It is superfluous for me to write to you”—in the sense that he should not need to write them further about this subject since they already knew the facts. — Stam, page 184
Macedonians (v.2) — A Roman province in the northern part of Greece. It included the cities of Berea, Thessalonica (the capital), Philippi, Amphipolis, Appollonia, Neapolis, and Nicopolis, all mentioned in the New Testament.
Achaia (v.2) — Greece, the area of the Corinthian church and other churches in the area like the one in Cenchrea (see Romans 16:1).
A year before (see 2 Corinthians 8:10), Paul had asked the members of the church in Corinth for contributions to bring to the believers in Jerusalem who were suffering. They immediately, enthusiastically agreed (see 2 Corinthians 8:11).
Paul took the story of their willingness to give and used to it encourage other churches located in Macedonia to give also. These other churches also agreed to give, even though their members were suffering persecution and were very poor (see 2 Corinthians 8:2).
The distinction was that the Macedonian churches agreed to give—and then actually took up a collection and gave. The Corinthian church, on the other hand, had stopped with agreeing. They still hadn’t collected any money. The time was coming to take the money to Jerusalem. Paul appointed a delegation led by Titus to travel to Corinth and collect the money so that, when Paul himself arrived, it would be ready.
Paul reminded the Corinthians what an embarrassment it would be to Paul (and to them) to find them unprepared—especially since several Macedonians would be traveling with Paul. These are the same Macedonians who gave—largely—because Paul had told them the Corinthians were giving.
Paul was determined to get the money. It would be much better if they willingly collected it themselves and had it ready when he arrived than if he had to scold them for it when he came.