Why did Pilate wash his hands before the multitude in Matthew 27?
Pilate washed his hands before the multitude because he could not prevail against the crowd or get them to listen; when a tumult was made, he publicly declared, "I am innocent of the blood of this just person," though the context denies that claim.
Les explains that in Matthew 27 the nation of Israel is really on trial more than Jesus. The crowd demanded Barabbas and rejected Jesus, while Pilate kept trying to convince them he could find nothing wrong in Jesus. Pilate saw he could prevail nothing, could not get to first base with these Jews, and they would not listen; rather, a tumult was made. So he took water and washed his hands before the multitude, saying, "I am innocent of the blood of this just person." Les immediately challenges that claim: "You think he is? No he isn't." The handwashing was therefore a public gesture of self-declared innocence, not actual innocence. Earlier in the context, Les reminds us that Christ was God, never laying aside His deity, only His glory. God the Son stood before that Roman governor, and unless that governor was saved, he will one day stand before the same one as Judge and Almighty God.
When Pilate saw that he could prevail nothing, but that rather a tumult was made, he took water, and washed his hands before the multitude, saying, I am innocent of the blood of this just person: see ye to it.