Albert Barnes on 1 Corinthians 4:18

Now some are puffed up. They are puffed up with vain confidence; they say that I would not dare to come; that I would be afraid to appear among them, to administer discipline, to rebuke them, or to supersede their authority, Probably he had been detained by the demand on his services in other places, and by various providential hinderances from going there, until they supposed that he stayed away from fear. And possibly he might apprehend that they would think he had sent Timothy because he was afraid to come himself. Their conduct was an instance of the haughtiness and arrogance which men will assume when they suppose they are in no danger of reproof or punishment.