Answer: In the previous Halacha we have discussed the general obligation of washing one’s hands (Netilat Yadayim) and we briefly discussed the reasons for this Mitzvah. Two of these reasons are: Firstly, the reason quoted by the holy Zohar which states that when one goes to sleep, one’s soul departs and one tastes the taste of death at which point an evil spirit rests upon one’s entire body. When one’s soul returns to one’s body upon awakening in the morning, the evil spirit remains on one’s hands and one must therefore wash one’s hands in order to remove it. Secondly, the reason mentioned by the Rosh is that since one’s hands are constantly in motion, we must assume that during one’s sleep, one must have touched places on one’s body that are unclean; thus, our Sages enacted that one must wash one’s hands in the morning.
Regarding the above question regarding whether or not one who awakens in the middle of the night and wishes to drink a glass of water must first wash one’s hands before one can recite the blessing on the water, this matter is indeed subject to a disagreement among the Rishonim. The Ra’ah maintains that one may not recite a blessing before washing one’s hands. The Rosh, however, disagrees and states that we can infer from the Gemara that according to the law, one need not wash one’s hands before reciting a blessing, for we see that our Sages enacted washing one’s hands only for Keri’at Shema and prayer; however, regarding other blessings, one may recite them even before washing one’s hands unless there is reason to think that one touched places on one’s body usually covered by clothing in which case one would have to wash one’s hands or rub them vigorously on one’s clothing regardless of the obligation to wash one’s hands in the morning.
Maran Ha’Shulchan Aruch (Chapter 4, Section 23) rules in accordance with the more lenient view on this matter. Thus, if one wakes up in the middle of the night and wishes to take a drink of water, one may do so even without washing one’s hands once one has rubbed his hands vigorously on his clothes. If one has slept while wearing clothing that covers one’s entire body, one need not rub one’s hands on one’s clothing and may recite the blessing and drink without further ado. (Similarly, if one wakes up in the middle of the night due to hearing thunder or seeing lightning, one may recite the prescribed blessing of “Shekocho U’Gvurato Maleh Olam” upon such events even without first washing his hands.) Nevertheless, one must take care not to touch the water one is drinking and only to touch the cup one is drinking out of, for an evil spirit still rests upon one’s hands.