Matthew 27v24, the washing of the hands was not only a symbolic custom of the day that showed innocence, but was also a ritual prescribed in the Jewish law (Deuteronomy 21:6-7; Psalm 26:6).

Matthew is the only writer to record Pilate washing his hands of guilt, just as he was the only writer to record Pilate's wife coming to him with the details of the dream she had about Jesus. 

Secular records her name as Claudia. She is the only one who spoke for, instead of against Jesus' life during the trial.

This dream, no doubt came from God, since Claudia would have had to dreamt it before she knew of Jesus being brought to Pilate. Not only did the Lord bare witness in Pilate's heart to the innocence of Jesus, but He also gave Pilate's wife a very clear message through this dream. 

Pilate was not innocent in the matter. Together, these instances proved that Pilate did not innocently condemn Jesus to death. Pilate will be trying to wash the blood of Jesus off his hands throughout eternity.

Just as God was faithful to show Pilate the truth in this situation, we can be sure that every person who has ever rejected Jesus has done it in spite of the conviction of the Holy Spirit in their heart (Romans 1:18-20).