These people had seen what Jesus did, and they reasoned from it. Others had doubted because they knew where Jesus came from (John 7:27). These answered with His works. If the Christ came, could He do more than this man had already done? Barnes explains, "It was a common expectation that the Messiah would work many miracles," and he points to Isaiah 35:5-6, where the blind see and the lame leap. Gill agrees: "The Jews expected many miracles to be wrought by the Messiah when he came." The question expects the answer no. In their minds, the signs had already made the case.

The question answers itself. No one could ask for more signs than Jesus had already given, and John says plainly that they "believed on him" (John 7:31). But their words spread. "The Pharisees heard that the people murmured such things concerning him," and with the chief priests they "sent officers to take him" (John 7:32). Jesus then said, "Yet a little while am I with you, and then I go unto him that sent me" (John 7:33). The people's talk moved the rulers to act against Him.

The KJV says "miracles"; the ESV says "signs." The KJV itself uses "signs" when John explains why he wrote his Gospel: "many other signs truly did Jesus... But these are written, that ye might believe" (John 20:30-31).

The people's hope rested on Old Testament promises of what God would do when He came to save. Barnes cites Isaiah 35:5-6: "Then the eyes of the blind shall be opened, and the ears of the deaf shall be unstopped. Then shall the lame man leap as an hart." The word "murmured" in John 7:32 describes quiet talk in the crowd, the same kind of talk John mentions at the start of the feast: "there was much murmuring among the people concerning him" (John 7:12).

John wrote his Gospel so that readers would do what these people did. He says the signs "are written, that ye might believe that Jesus is the Christ, the Son of God" (John 20:31). This question is a small picture of that purpose. Plain people looked at what Jesus had done and drew the right conclusion.

But the passage is honest about the cost. As soon as the people's belief became talk in the crowd, the rulers moved to arrest Him (John 7:32). Matthew Henry's Concise Commentary notes, "The discourses of Jesus convinced many that he was the Messiah; but they had not courage to own it." Faith that sees clearly still has to decide whether to speak.