Albert Barnes on Matthew 27:23

And the governor said, Why? Luke informs us that Pilate put this question to them three times, so anxious was he to release him. He affirmed that he had found no cause of death in him. He said, therefore, that he would chastise him, and let him go. He expected probably, by causing him to be publicly whipped, to excite their compassion, to satisfy them, and thus to evade the demands of the priests, and to set him at liberty with the consent of the people. So weak and irresolute was this Roman governor! Satisfied of his innocence, he should at once have preferred justice to popularity, and acted as became a magistrate in acquitting the innocent.

Let him be crucified. Mt 27:39. Luke says they were instant with loud voices demanding this. They urged it. They demanded it with a popular clamour.

(w) "Let him be crucified" Mt 21:38,39