What does Galatians 2:10 mean?

Paul has reported to the Galatians that the other apostles, Jesus' own disciples during His time on earth, had given their full approval both to his own role as an apostle and the message he preached of salvation through God's grace and not through following the Law. This was their opportunity to correct Paul's preaching, to rebuke his message, or to declare where he was wrong. Their actions prove that they did not see error in Paul's gospel—they recognized it as the truth. So, they declared their fellowship with Paul and made it clear that they approved of his ministry.

Now Paul adds that Peter, James, and John did ask him to do one extra thing in his ministry to the Gentiles. They asked him to remember the poor. Paul eagerly agreed. In fact, he had likely come to Jerusalem from Antioch in Syria to bring famine relief from people in that part of the world (Acts 11:29–30). Paul's entire ministry was marked by urging Christians to give support and care to those who were struggling (1 Corinthians 16:1–3).