24So when Pilate saw that he was gaining nothing, but rather that a riot was beginning, he took water and washed his hands before the crowd, saying, “I am innocent of this man’s blood; see to it yourselves.” 25And all the people answered, “His blood be on us and on our children!” 26Then he released for them Barabbas, and having scourged Jesus, delivered him to be crucified.
Israel uses a common idiom to denote responsibility for their actions and their request. By so doing, they place the responsibility for Christ’s crucifixion on themselves. The irony I find is that the only way for them to receive cleansing, right standing before God, is by the very same blood of Jesus Christ. The cry that the people make in this scene are the very same words (different thought behind it of course) that one makes in calling Jesus to be Savior and Lord of their life.