Last week, at the Shmini Azeret table, I was asked for a dvar Torah. I said that I didn’t have anything to say. But then I said I would briefly speak on something upon which I had been researching that morning. I had taken out Tannaitic sources about sleep and beds and was looking into Rashi’s and Tosafot’s comments upon them. Just as I had started, mentioning the link between death and sleep (the most obvious source is the beraisa on ברכות נז:, which speaks about sleep being a negligible amount of death, though there are others (עין כגון בגיטין ע. וברכות סא:)) and he asked if that’s why we’re supposed to wash our hands in the morning. Though I said, “No,” I said I would respond to that after my brief presentation of sources.
So I did. There are no sources connecting רוח רעה (evil spirit) to sleep at all in Talmudic sources (there is however one source connecting this evil spirit to beds: תנא אוכלין ומשקין תחת המטה אפילו מחופין בכלי ברזל רוח רעה שורה עליהן – “It was taught: Foods and drinks under the bed – even covered in iron vessels, an evil spirit rests upon them.” (פסחים קיב.)), so it is errorful to attribute to either the tannaim, amoraim, or even the editors of the Talmuds, etc. this idea of evil spirit descending upon a person while sleeping. So whence is this idea?
It is none other than our sainted Rashi who came up with this idea. Now before one criticizes this great sage, one should appreciate his חידוש (novella) on a difficult סוגיא (pericope) in the Babylonian Talmud. The section in question is the following (bShabbat 108b-109a):
אמר שמואל טובה טיפת צונן שחרית ורחיצת ידים ורגלים בחמין ערבית מכל קילורין שבעולם.
תניא נמי הכי אמר רבי מונא משום רבי יהודה טובה טיפת צונן שחרית ורחיצת ידים ורגלים ערבית מכל קילורין שבעולם הוא. היה אומר יד לעין תיקצץ, יד לחוטם תיקצץ, יד לפה תיקצץ, יד לאוזן תיקצץ, יד לחסודה תיקצץ, יד לאמה תיקצץ, יד לפי טבעת תיקצץ, יד לגיגית תיקצץ, יד מסמא, יד מחרשת, יד מעלה פוליפוס.תניא רבי נתן אומר בת חורין היא זו ומקפדת עד שירחוץ ידיו שלש פעמיםShmuel said: A drop of cold water in the morning, and bathing the hands and feet in hot water in the evening, is better than all the eye-salves in the world.
It was taught likewise: R. Muna said in R. Judah's name: A drop of cold water in the morning and bathing the hands and feet in the evening is better than all the eye-salves in the world.
He [R. Muna] used to say: Hand to the eye, let it be cut off; the hand to the nose, let it be cut off: the hand to the mouth, let it be cut off; the hand to the ear, let it be cut off; the hand to the vein [opened for blood letting], let it be cut off; the hand to the membrum, let it be cut off; the hand to the anus, let it be cut off; the handto the vat, let it be cut off, the hand leads to blindness, the hand leads to deafness, the hand causes a polypus.
It was taught, R. Nathan said: She is a freewoman and she is careful/insists until he washes his hands three times.
My best surmisal is that, from the surface reading of this section of the Talmud, it would seem that Rabbi Nathan is speaking about what had been mentioned in the previous text, that he is speaking upon the evening washing of one's hands and feet. It may thus be that the lady of the house enforces her man to wash his hands really well before touching stuff in the house, etc., perhaps because women are more mindful of cleanliness than men(?).
However, Rashi didn't take my approach, so he had a weird sounding set of texts in front of him. What to do? Starting from his comment on Rabbi Muna's statement (ד"ה יד לעין: שחרית קודם שיטול ידיו), he develops his חידוש of these texts speaking about washing one's hands in the morning(!) until the end of this set of texts (see esp. his comments on Rabbi Nathan's beraisa).
One has to appreciate the brilliance of the way Rashi handles this gemarra (section of the Talmud), as it is definitely an odd section. However, it's not necessarily the read understood by other ראשונים (medieval commentators) (see esp. the Rambam's laws on washing hands in the morning (הלכות תפילה ז:ד)(which is taken from Berakhos 60b) until the Tur came along and codified Rashi's approach (OC 4:2), which has been taken on by the Shulkhan Arukh and subsequent halakhic works.
However, even if one finds Rashi's reason unsatisfactory, there are still other reasons why Jews are supposed to wash their hands in the morning: the Rosh says it is due to our hands being active in the night, touching dirty places and the Rashba says it is due to being a new creation. While one can check into these sources (unless you want me to post their locations), I think that the Rambam has the understanding of our sages well in hand, as hand washing is on account of prayer (why else would hand washing be so far back in the list of blessings on Berakhos 60b?).
(The MO don't always bring a lack of sources, Chardal.)