Parsha Mitzvot: Ki Tisa: Mitzvah 106 – Concept 331
“You shall make a copper Laver and its base of copper, for washing; place it between the Tent of Meeting and the Altar, and put water there. From it, Aaron and his sons shall wash their hands together with their feet. When ever they come to the Tent of Meeting, they shall wash with water and not die, or when they approach the Altar to serve, to raise up in smoke a fire-offering to God. They shall wash their hands and feet and not die. It shall be for them an eternal decree, for him and his offspring for their generations.” (Exodus 30:18-21) A cohen must wash his hands and feet before doing the service. (Rambam, Hilchot Biat Hamikdash – The Laws of Entering the Temple)
The numerical value of Aharon is 256, which corresponds to the Chayot that have 256 wings. They have such fear of God that their wings perspire and drip so much sweat that they form the Dinor River in which they and humans can wash. This is why the verse (Isaiah 44:23) says, “Sing glad song – ‘Ranu’ =256 – O heavens for Hashem has done.” Each time the Cohen washes his hands and feet, he is washing in the fear and awe of these mighty angels, and preparing himself to serve God at ever increasing heights. (Perush HaTorah L’Ba’alei Tosafot)
We reenact this process when we wash our hands in the morning and before prayer.