Paul asks whether he is not free, not an apostle, whether he has not seen Jesus our Lord and whether the Corinthians are not his work in the Lord. Even if he is not an apostle to others, he is to them, for they are the seal of his apostleship. He has the right to eat and drink, to take along a believing wife as the other apostles, the Lord's brothers and Cephas do, and to refrain from working with his hands, as Barnabas does.
Paul defends that right with examples: a soldier does not serve at his own expense, one who plants a vineyard eats its fruit and a shepherd drinks the milk of the flock. The law of Moses supports him too, commanding that the threshing ox not be muzzled, and so does a rule of the Lord: those who proclaim the gospel should get their living from the gospel. Yet Paul has used none of these rights, so as not to put an obstacle in the way of the gospel of Christ.
Preaching the gospel is no ground for boasting for him, but a necessity, and woe to him if he does not preach it! His reward is to preach it free of charge. Though free from all, he made himself a servant to all in order to win more: to the Jews he became like a Jew, to those under the law like one under the law, to those outside the law like one outside it, to the weak he became weak. He became all things to all people so that he might save some, and he does it all for the sake of the gospel.
Paul ends with the image of runners in the stadium: only one receives the prize, but they should run so as to win it. Everyone who competes exercises self-control in all things, and they do it for a perishable wreath, we for an imperishable one. Paul runs with purpose, not like one beating the air, and disciplines his body so that, after preaching to others, he himself will not be disqualified.