Hung Out To Dry
‘A Roof With A Parapet 10 Tefachim High Is Not Included’
(Bava Basra 63b-64a)
The Required Height Of A Parapet On A Roof
The Torah commands, “Make a parapet for your roof” (Devarim 22:8), but its required height is not indicated. The first source to provide a required height is Sifrei (Ki Seitzei 67), “Its circumference, its height – three tefachim; its walking area – 10 tefachim.” Many commentators toil over this statement. The Semag (Aseh 49) explains that a well needs a parapet three tefachim high while the parapet of a roof must be 10 tefachim high. “Circumference,” the Semag says, means a well, which is usually round, while “walking area” refers to a roof. (The Netziv on Sifrei explains that roofs in Middle East, if they don’t have a dome, are usually flat so that they can be used in the long dry season.)
However, Sefer Hayereim (234 [45 in the old editions]) maintains that “circumference” refers to a parapet’s required height while “walking area” refers to a roof’s height. In other words, a roof less than 10 tefachim from the ground doesn’t need a parapet. The Rambam (Hilchos Rotzeach Ushemiras Hanefesh 11:3) writes that a parapet must be at least 10 tefachim high in order to prevent someone from falling. The Raavad and Kesef Mishneh, though, interpret “walking area” to mean the area of a roof that is most used. The parapet there must be 10 tefachim high but the rest of “its circumference” around the roof needs to be only three tefachim (see Tosafos Harosh, Mo’ed Kattan 11a, s.v. “Ve’osim”).
Exclusions
The Vilna Gaon (see Choshen Mishpat 214:35; 427:3) cites our mishnah (supra 61a) and Gemara as the source for the Rambam’s statement (Hilchos Mechira 24:16, 25:2) that a “person who sells a house is assumed to exclude its roof from the sale if its parapet is 10 tefachim high.” A roof with a parapet at least 10 tefachim high is defined as a separate property, not necessarily serving the house, and not included in the sale unless so specified.
With His Own Two Hands
The Gemara (Kiddushin 70a) relates that although Rav Nachman was a highly respected talmid chacham and av beis din, he insisted on building the railing around his roof himself in order to fulfill the mitzvah of “Make a parapet for your roof.”
Prohibition Against Relying on Miracles
The Sefer Hachinuch, in explaining the reason for this mitzvah, writes that although “man does not even bruise a finger here on earth until it is decreed in Heaven, he must protect himself from danger, for when Hashem created the world, He based it on the laws of nature. He decreed that fire would burn and water would extinguish flames. And if a large rock falls on a man’s head, or if he falls from a high roof, according to the laws of nature, a man will die. Thus, the Torah commanded us to safeguard our homes and neighborhoods to prevent death through our own negligence and to avoid risking our lives [and the lives of others] by relying on miracles.”
A Mitzvah-Article Like Any Other
The Shibolei Haleket (Chanukah 185) writes that a parapet, like tzitzis, a lulav, or a sukkah, is a mitzvah-article and care should be taken not to tread on it. Rabbi Chaim Kanievsky (Hilchos Shecheinim 36) writes that laundry may be hung on a parapet because household use of mitzvah-articles is not considered debasing. As proof, he cites an account in the Gemara (Sukkah 10b) of Menimin, Rav Ashi’s servant, hanging his wet shirt on a sukkah and being reproached by Rav Ashi, who said other people might think it is permitted to use an article that can become impure as s’chach. Rav Ashi, however, did not rebuke him for treating the sukkah with disrespect!