“Then” explicitly connects Peter’s question to the preceding verse, although, technically, it only says that he asked a question next. But we may assume that he is taking up the question of resolving offenses. We can expand his question in verse 21 this way: “I understand that if my brother sins against me, I must confront him. I also know what to do if he refuses to listen. But what if the first step works? What if he listens? I presume I have to forgive him. But what if he offends me repeatedly?