Paul has just said he would give up meat rather than harm a brother. Barnes notes that Paul "mentioned his willingness to deny himself" and now shows it from his own life. But first he must show that his self-denial is a choice, not a sign that he lacks rights, because some at Corinth questioned whether he was a true apostle. Matthew Henry says "false brethren questioned his apostleship, and were very industrious to lessen his character." Each question presses one point. He is an apostle. He is free; Gill explains that "no man had any authority over him." He has seen the Lord. And the Corinthians themselves are the fruit of his work.

Each question expects the answer yes, and Paul makes it explicit: "If I be not an apostle unto others, yet doubtless I am to you: for the seal of mine apostleship are ye in the Lord" (1 Corinthians 9:2). Then he begins his defense: "Mine answer to them that do examine me is this" (1 Corinthians 9:3), and goes on to list the rights he has as an apostle (1 Corinthians 9:4-6). Gill says the Corinthians' conversion "served him instead of a letter testimonial and recommendatory."

Barnes explains that "the apostles were appointed to be witnesses of the life, doctrines, death, and resurrection of the Lord Jesus," so having seen the Lord mattered. Paul saw Him on the road to Damascus (Acts 9:3-5, 17), and he writes that "last of all he was seen of me also" (1 Corinthians 15:8); Barnes points to both passages. Paul had founded the church in Corinth, staying "a year and six months" (Acts 18:11). The order of the first two questions differs by text: the Textus Receptus behind the KJV reads "apostle" first and "Jesus Christ our Lord," while the Greek text behind the ESV puts "free" first and reads "Jesus our Lord."

These questions open the whole argument of 1 Corinthians 9. Paul has every right of an apostle, and he chooses not to use them: "Nevertheless we have not used this power; but suffer all things, lest we should hinder the gospel of Christ" (1 Corinthians 9:12). He proves his freedom before he shows how he spends it: "though I be free from all men, yet have I made myself servant unto all, that I might gain the more" (1 Corinthians 9:19).

Paul's strongest evidence is not a title but people. Barnes says that in the Corinthians' conversion "God blessed and owned this claim." Matthew Henry adds, "It was aggravated ingratitude for this people to call in question his authority," since they owed their faith to his preaching.