Deuteronomy 21:6 - Clarke's commentary and critical notes on the Bible

And all the elders of that city, that are next unto the slain man, shall wash their hands over the heifer that is beheaded in the valley: Shall wash their hands over the heifer - Washing the hands, in reference to such a subject as this, was a rite anciently used to signify that the persons thus washing were innocent of the crime in question. It was probably from the Jews that Pilate learned this symbolical method of expressing his innocence.