In Mei HaShiloach, the Isbitzer Rebbe comments on the verse "Let Aaron and his sons wash their hands and feet in water drawn from [the copper laver]" (Exodus 30:19). He states that the the priests cleanse themselves with water to remove the layers of their own personal desires and interests from their service, so that everything they do in worshiping God is for the sake God's will—not their own.
My study partner, Cantor Bob Scherr, pointed out that this is like the intention of the ritual washing of hands before eating. This act is called netilat yadayim, the "taking up of hands," and that is the phrase used in the blessing recited after washing. Why is it called "taking up hands"? Why not "washing hands"? One answer is that, before we eat, we should elevate our consciousness about food.
Have you ever hungrily gobbled down a meal only to realize, afterward, that you missed the pleasure of tasting and experiencing it? If we eat just in order to satisfy our hunger, we will draw no lasting satisfaction from eating. The experience of deepest pleasure comes from mindfulness and self-awareness. When we eat just to satisfy a craving, like scratching an itch, our pleasure is limited to the moment of consumption. But, when we eat with a real awareness that the food we eat is a gift, and that by eating it we become part of something larger than ourselves, there is a possibility for a lasting pleasure that enters deeply into our souls.
This is the teaching of the Isbitzer extended from the ancient Kohanim to our daily lives. When we take the time to wash away the layers of our immediate and momentary cravings, we lift ourselves up into the joyous realm in which we allow God to enter into us.