It is well known that one must wash their hands before eating bread, and make a blessing. This is by Rabbinic edict. There is then another Talmudic rule that one should make the blessing of ‘Al Netilas Yadayim’ in the morning as well. Although no reason is given, the Rosh (Berachos 9:23) explains that when one sleeps their hands travel and they certainly touched ‘unclean’ places. (We will discuss the idea of touching impure places more at length later). They must therefore wash their hands before davening.
A more Kabbalistic reason is given by the Rashba (Shut 191): When one awakens they are like a new person. This reality necessitates our immediate thanks and appreciation to Hashem, which is comparable to the Avodah of the Kohen in the Beis Hamikdash. Just as he must wash his hands from the Kiyur we too must wash our hands from a cup.
The Mishnah Berurah quotes both of the above reasons, and writes that we necessitate washing for either of them, albeit not with a Bracha. Therefore if one was up all night (or slept with gloves) they would still have to wash their hands.
There is a third reason described by the Gemara in Shabbos (109b) is Ruach Ra’ah, a metaphysical negative ‘spirit’ that rests on a person overnight, and one is cautioned against touching any facial orifice before washing your hands. [This is also the reason why it’s necessary to wash three times, and with a cup, which we will discuss later]. This seems to be related, in Halachic literature, to an idea presented by the Arizal: The Gemara says that sleep is 1/60th of death. The Arizal explains that when one awakens all vestiges of “death” leave him, aside from his hands which still retain some influence (and no blessings should be recited in that state). One must therefore wash his hands before being able to say any blessings.
The first two reasons necessitate a blessing (according to their respective authors) the third reason does not necessitate a blessing, but does impel one to wash ones hands as soon as possible after awaking.
Next we will discuss other occasions that necessitate Halachic hand washing.