Paul has to clarify his earlier instruction. The church was tolerating sin inside it (1 Corinthians 5:2), and Paul makes clear he never meant they should avoid all the sinners outside it (1 Corinthians 5:10). Paul's first question sets the limit of his own authority. Barnes paraphrases Paul's point: "I have no authority over them; and can exercise no jurisdiction over them." His second question points to what they already practiced. Gill says Paul "appeals to their own conduct," since they dealt only with those "within the pale of the church." Together the questions show where the church's responsibility really lies.

Paul answers both questions in the next verse. On those outside: "But them that are without God judgeth." On those inside: "Therefore put away from among yourselves that wicked person" (1 Corinthians 5:13). Paul goes straight on to another failure in the same area, believers taking one another to law "before the unjust" (1 Corinthians 6:1).

The phrases "without" and "within" translate the Greek exo, outside, and eso, inside. Paul uses "them that are without" for unbelievers elsewhere too: "Walk in wisdom toward them that are without" (Colossians 4:5). Paul refers to an earlier letter (1 Corinthians 5:9) and clarifies what he meant by it (1 Corinthians 5:10-11). Gill says reference "seems to be had" to Deuteronomy 17:7 in Paul's closing command, where the Septuagint (the ancient Greek translation of the Old Testament) uses very similar wording: in the KJV, "So thou shalt put the evil away from among you."

This question puts judgment in its proper place. The church is not called to police the world. Barnes says those outside the church "are under the direct and special government of God," and "It is not ours to pronounce sentence upon them, or to inflict punishment. God will do that." Gill adds that though such people are not under church discipline, "yet they shall not go unpunished." God remains the Judge of all.

But the church does have a responsibility for its own life. Matthew Henry explains that those within "are professedly bound by the laws and rules of Christianity." Paul does not want believers to leave the world (1 Corinthians 5:10). He wants them to be honest about sin among themselves, so that the church can be what Christ made it.