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Masechet Shabbos Daf 12
May. 27th, 2020 10:13 amDaf 12
The Mishna continued with additional gezeirahs to prevent violating Shabbos.
What's a gezeirah again? The Torah has particular parameters to its mitzvot, and Deuteronomy is clear that you're not supposed to either add or subtract from those parameters. But elsewhere in Deuteronomy it says that if you build a house that has a roof that one can stand on, you must build a fence around the roof so no one can fall off. The Gemara in Bava Kamma explores the actual halacha of building a literal fence, but elsewhere in the Gemara this concept of the fence is used as a legally binding metaphor for the idea that the Rabbis can impose fences around the law to protect a person from carelessly transgressing.
This can be a difficult grey area to navigate. When does a fence go too far so that it is in effect imposing new halacha? A lot of the Gemara on this page is about this question. There is a basic principle that you can make a fence to prevent you from violating a Torah prohibition (D'oraysa), but you can't make a fence to prevent you from violating a Rabbinic prohibition (D'Rabbananan), because that would be a fence around a fence and that's too far toward the forbidden practice of adding laws to the Torah. The problem is that there are disputes about what qualifies as D'oraysa, so some might add fences around disputed practices, and it's important to be clear about what halachic understanding underpins the gezeirah.
This awareness is particularly important in interpreting halacha because the rules of d'oraysa rules are different than the rules for d'rabbanans in a bunch of ways. It's a lot easier to cheat around a d'rabbanan prohibition in extenuating circumstances, it's a lot easier to say that a scenario simply doesn't apply. This is one of the ways we maintain the clear separation between d'oraysa and d'rabbanan prohibitions to make sure we're not violating the prohibition of adding or subtracting to the law. On this daf there's a place where the Gemara even argues that it's okay to not observe one particular gezeirah if you're a distinguished scholar with extremely strong self-discipline and you just know that you won't accidentally make this mistake. This position is immediately attacked, but it makes it clear how lenient the Gemara is willing to be about certain gezeirahs.
One set of gezeirahs involves lamps, which were obviously oil lamps back then, not electric lights. If you light a lamp before Shabbos it can be left alone to burn out, but you are not allowed to adjust a lamp on Shabbos because it essentially re-activates the prohibition of lighting a fire to bring the flame toward new fuel. So that's a clear D'oraysa prohibition, and the Rabbis enact a gezeirah forbidding using that light for certain activities that require very fine, precise examination under the light, for fear that one would tilt the lamp toward themselves to see better. Examples are delousing a garment by lamplight and reading by lamplight.
This leads to the question of whether delousing a garment on Shabbos is permitted at all. Answer is it's a machlokess, some hold it's generally okay even if you kill a louse, some hold it's okay as long as you don't kill the lice, some hold that it's not okay because you might accidentally kill a louse.
So the breakdown is based on a) whether or not you believe it's possible to delouse a garment without killing any lice and b)whether or not you believe it's permitted to kill a louse on Shabbos. It's forbidden to kill animals on Shabbos, but are lice 'animals'? The forbidden melachot theoretically derive from the acts done in building the Mishkan in the wilderness, so there's a plausible argument to distinguish large animals killed for the skins, vs. tiny bugs that were not killed as part of building the Mishkan. R' Eliezer considers all life to be sacred on Shabbos even down to lice. Beis Shammai agrees, but Beis Hillel permits killing a louse on Shabbos, and the halacha is as usual with Beis Hillel.
The Mishna continued with additional gezeirahs to prevent violating Shabbos.
What's a gezeirah again? The Torah has particular parameters to its mitzvot, and Deuteronomy is clear that you're not supposed to either add or subtract from those parameters. But elsewhere in Deuteronomy it says that if you build a house that has a roof that one can stand on, you must build a fence around the roof so no one can fall off. The Gemara in Bava Kamma explores the actual halacha of building a literal fence, but elsewhere in the Gemara this concept of the fence is used as a legally binding metaphor for the idea that the Rabbis can impose fences around the law to protect a person from carelessly transgressing.
This can be a difficult grey area to navigate. When does a fence go too far so that it is in effect imposing new halacha? A lot of the Gemara on this page is about this question. There is a basic principle that you can make a fence to prevent you from violating a Torah prohibition (D'oraysa), but you can't make a fence to prevent you from violating a Rabbinic prohibition (D'Rabbananan), because that would be a fence around a fence and that's too far toward the forbidden practice of adding laws to the Torah. The problem is that there are disputes about what qualifies as D'oraysa, so some might add fences around disputed practices, and it's important to be clear about what halachic understanding underpins the gezeirah.
This awareness is particularly important in interpreting halacha because the rules of d'oraysa rules are different than the rules for d'rabbanans in a bunch of ways. It's a lot easier to cheat around a d'rabbanan prohibition in extenuating circumstances, it's a lot easier to say that a scenario simply doesn't apply. This is one of the ways we maintain the clear separation between d'oraysa and d'rabbanan prohibitions to make sure we're not violating the prohibition of adding or subtracting to the law. On this daf there's a place where the Gemara even argues that it's okay to not observe one particular gezeirah if you're a distinguished scholar with extremely strong self-discipline and you just know that you won't accidentally make this mistake. This position is immediately attacked, but it makes it clear how lenient the Gemara is willing to be about certain gezeirahs.
One set of gezeirahs involves lamps, which were obviously oil lamps back then, not electric lights. If you light a lamp before Shabbos it can be left alone to burn out, but you are not allowed to adjust a lamp on Shabbos because it essentially re-activates the prohibition of lighting a fire to bring the flame toward new fuel. So that's a clear D'oraysa prohibition, and the Rabbis enact a gezeirah forbidding using that light for certain activities that require very fine, precise examination under the light, for fear that one would tilt the lamp toward themselves to see better. Examples are delousing a garment by lamplight and reading by lamplight.
This leads to the question of whether delousing a garment on Shabbos is permitted at all. Answer is it's a machlokess, some hold it's generally okay even if you kill a louse, some hold it's okay as long as you don't kill the lice, some hold that it's not okay because you might accidentally kill a louse.
So the breakdown is based on a) whether or not you believe it's possible to delouse a garment without killing any lice and b)whether or not you believe it's permitted to kill a louse on Shabbos. It's forbidden to kill animals on Shabbos, but are lice 'animals'? The forbidden melachot theoretically derive from the acts done in building the Mishkan in the wilderness, so there's a plausible argument to distinguish large animals killed for the skins, vs. tiny bugs that were not killed as part of building the Mishkan. R' Eliezer considers all life to be sacred on Shabbos even down to lice. Beis Shammai agrees, but Beis Hillel permits killing a louse on Shabbos, and the halacha is as usual with Beis Hillel.