In addition to the reasons mentioned, the Sages of the Talmud state (Shabbat 108b) that one must be careful that her hands do not touch her mouth, nose, eyes, or ears before washing her hands in the morning because there is a ru’aĥ ra’ah (evil spirit) which rests upon one’s hands after sleep, and it is likely to damage those organs. Only after she washes her hands three times alternately will the ru’aĥ ra’ah disappear and, subsequently, the danger caused by touching any of her bodily orifices will be eliminated.
Although the main reason for netilat yadayim is to prepare and sanctify oneself for praying Shaĥarit and for the service of a new day, and it is for this reason that the Sages instituted the berakha of al netilat yadayim, we are also careful about the ru’aĥ ra’ah and therefore take care to wash our hands three times alternately. This means that we first wash the right hand, then the left, then again the right and left, and again right and left.
Prior to washing, one must take care not to touch those organs that open towards the inside of the body – such as the mouth, nose, ears, and eyes (SA 4:3-4; MB 13). Similarly, one must be careful not to touch food or drink before washing (MB 4:14).
The Kabbala teaches (see Zohar 1:184b) that at night, when one falls asleep and remains inanimate, without thought or action, she experiences a taste of death and a spirit of impurity (ru’aĥ tum’a) rests upon her. This is in line with the Sages’ statement (Berakhot 57b), that sleep is one-sixtieth of death. The essence of human grandeur lies in the ability to think, feel, and engage in activities leading to the rectification of the world (tikun olam). During sleep, when dormancy spreads throughout the body, one loses, to a certain extent, the image of God (Tzelem Elokim) within her, and ru’aĥ ra’ah rests upon her. When she awakens from her sleep and her consciousness returns, the ru’aĥ ra’ah disappears, remaining solely on the extremities of her hands. By washing one’s hands three times alternately, the spirit of impurity is removed.
In order to completely eradicate the ru’aĥ ra’ah, one must begin washing her right hand, which symbolizes the attribute of ĥesed. Therefore, one should take the washing cup initially in her right hand and pass it over to her left, so that she pours the water over the right hand first and then the left, continuing this way until she has washed each hand three times (see Kaf Ha-ĥayim 4:12).
Some explain that the main damage caused by the ru’aĥ ra’ah is spiritual; if one were to touch her eyes or ears before washing, her inner sense of vision and understanding would be adversely affected, and on that day she would be like a blind and deaf person concerning matters of Torah and faith. Similarly, if she were to touch her mouth or nose, the ru’aĥ ra’ah would harm her spiritual senses of eating and smelling (Kaf Ha-ĥayim 4:19, based on Solet Belula).