Spirit of the Law: Netilas Yadayim; Sanctifying the Hands

The Rashba, zt”l, explains that we wash our hands each morning like a kohein must wash his hands and feet to prepare to serve in the mikdash. The Baal Shem Tov, zt”l, explained the significance of this mitzvah.
“When the verse warns that we should not fall into arrogance, it states that we should not mistakenly think, 'כחי ועצם ידי עשה לי את החיל הזה'—‘My power and the force of my hands brought me all this wealth.’ We see that feeling hubris comes from a mistaken attitude regarding our actions which are the work of our hands. The kohein sanctified his hands to wash away such mistaken attitudes and understand that Hashem gives us the strength and enables us to do his will.
“The kohein also sanctified his feet to symbolize that we are washing away the הרגל, our tendency to do things by rote without thinking about it and without freshness. In order for avodah to be kosher it must be done with humility and with freshness, never by rote.”
The Mekor Chaim, zt”l, explained why we do not wash our feet every morning as well as our hands. “Although washing each morning represents sanctifying ourselves like the kohein who was obligated to wash from the כיור each day, those who do not go barefoot are not required to wash their feet, unlike a kohein in the beis hamikdash. This is because now that the beis hamikdash has been destroyed it is very difficult to purify our feet. Although we can learn to act with humility it is virtually impossible to completely purify ourselves from acting by rote.”