What does Matthew 27:18 mean?

Pilate is trying to come up with a scheme to release Jesus from custody. At least part of that is common sense: according to this verse, Pilate understood that the Jewish religious leaders were trying to use Roman power to eliminate a rival. Given his existing awareness of Jesus (Matthew 21:10–11) and private interviews (John 18:33–36), Pilate has seen through their false accusations.

On the other hand, Pilate had to be careful. History notes that Pilate habitually antagonized the Jewish people, resulting in several ugly incidents. This was not ideal in the eyes of higher Roman authorities. With a swollen population, and an impending religious holiday (Matthew 27:15), Jerusalem would have been like a fuse waiting to be lit. As Pilate is likely realizing, there is a considerable crowd forming, and they are being manipulated by Jewish religious leaders (Matthew 27:20, 24; Mark 15:11, 15). Adding to the complexity, Jesus' enemies are making claims about insurrection (Luke 23:2). If he appears to be going soft on such crimes, the region could become unstable. Pilate does not want to release Jesus without good cause and risk provoking the powerful chief priests to stir up trouble of their own.

The easiest way out would be if the people themselves, the crowds, would select Jesus as their choice for the prisoner to be released at Passover. Pilate released one every year according to the people's wishes. He could be done with the entire issue if they would call for Jesus. The selection of a "notorious" murderer and rebel (Matthew 27:16; Mark 15:7) is a clear attempt to make the choice obvious.