Why is it that we have to wash our hands before eating bread but not for other food? I’ve heard that the reason for washing our hands is because “physical cleanliness is a prerequisite for spiritual holiness.” If the reason for washing our hands is because of physical cleanliness, then how does merely rinsing our hands without soap lead to cleanliness?
Besides cleanliness and holiness, the immediate reason the rabbis required washing before bread is to keep alive the memory of the proper treatment of teruma (the first priestly tithe that may be eaten only by kohanim and their immediate families, and that must be eaten only in the absence of any tum’ah – ritual defilement). Torah law places great emphasis on ensuring that teruma (and those who eat it) should not become defiled (see, for instance, Leviticus 22:4).
One aspect of a Kohen’s obligation to ensure that his teruma remained pure was to protect his hands from contact with any object or liquid that might defile them. Even if a kohen should simply become distracted from protecting them (as is unavoidable through a normal, busy day), he would be required to wash them in a way that reflects the preparatory washing in the Temple (see Exodus 30:18).
So that we shouldn’t lose our attachment to these laws through long centuries of disuse (for technical and historic reasons, kohanim do not actually eat teruma in our time), the rabbis decreed that all Jews should wash in a similar way before meals involving bread (which, by the way, was the most common food made from teruma grains).
I hope this makes things a bit clearer,
Rabbi Boruch Clinton