Sleeping Alone

It is generally forbidden to sleep alone in a house. The sages say that “anyone who sleeps alone in a house will be seized by Lilith.”(1)  Lilith is the name of a terrifying female demon who is said to cause bodily harm, death, or nocturnal emissions.(2)  Some authorities hold that Lilith only attacks males, while others say that she doesn’t differentiate between males and females. Le'halacha we don't differentiate,  and so women should also avoid sleeping alone in a house.(3)  This applies to any dark room that has no light coming in, so it doesn't matter night or day.(4)  Same too, it is not advisable to leave a baby alone in a house while sleeping in a crib.(5)

Many authorities rule that “in a house” actually means “in a room.”(6) According to this approach, it is forbidden to sleep alone in a room even if there are other people in the house. (7) However, if there are indeed other people in the house, simply leaving the door of the room open,(8) or perhaps even just unlocked,(9) will serve to eliminate the Lilith-related concerns. 

Nevertheless, other authorities rule that “in a house” is to be taken literally. According to this approach, as long as there are other people in the house, it is permitted to sleep alone in a room, preferably with the door open, but common custom is to allow it even if the door is closed or locked.(10) The general custom is to be lenient and as long as there are people in the house then it is Ok. Same too It is very difficult for one sleeping alone in a hotel room to comply with this view, as the doors generally lock automatically when closed. So too, there are many situations when leaving a door open or unlocked in a hotel raises some serious security and privacy concerns.

One who has no choice but to sleep alone in a house is advised to leave a light on, which is said to keep away Lilith and all other harmful spirits. This may be a nightlight, a hall light, or a light from another room that illuminates the room one is sleeping in. Even moonlight or streetlights are adequate for this purpose.(11)

1. Shabbat 151b; Orchot Chaim 48 of Rav Eliezer Hagadol.

2. Zohar, Pekudei 276b.

3. Kaf Hachaim, OC 239:17.

4. Rif; Rosh; Eishel Avraham 239. But see Zohar Tazria 45a.

5. Orchot Chaim 48.

6. Magen Avraham 239.

7. Kitzur Shulchan Aruch 71:2; Mishna Berura 239:9; Shaar Hatziun 239:17. This was the opinion of the Chazon Ish. Orchot Rabbeinu Vol. 1 p.93, Vol. 3 p. 226.

8. Mishna Berura 239:9; Shaar Hatziun 239:17; Shulchan Hatahor 241:10.

9. Chelkat Yaakov, OC 57.

10. Aruch Hashulchan, YD 116:18.

11. Shulchan Aruch Harav, Shemirat Haguf V’hanefesh, Kuntres Acharon 2.

12.  Maaseh Rav 221