QUESTION: The Gemara says that an oil lamp may not be moved on Shabbos, even according to Rebbi Shimon who is lenient with regard to Muktzah, because it is "Huktzah l'Mitzvaso" -- it is set aside for the Mitzvah [of lighting the Shabbos candles].

Why does the Gemara need to give the reason of "Huktzah l'Mitzvaso" to explain why the lamp may not be moved even according to Rebbi Shimon? Rebbi Shimon agrees that one may not move a lamp that is lit because it is a "Basis l'Davar ha'Asur" (46b-47a; see Insights there). Why, then, does the Gemara give the reason of "Huktzah l'Mitzvaso" if the reason of "Basis" prohibits the lamp from being moved while it is lit? (SEFAS EMES)

(The answer cannot be that the reason of "Huktzah l'Mitzvaso" is necessary to prohibit the oil that drips out while the lamp is lit (see Tosfos) or to prohibit taking oil from the lamp as it begins to go out (see Rashi 44a, DH Min ha'Ner and DH Kavah, and Insights to 44:1), because the Gemara implies that according to Rebbi Shimon, the person did not anticipate using any of the oil before the candle went out, and therefore it is Muktzah Machmas Isur and not just "Huktzah l'Mitzvaso" -- see Rashi DH k'Ein. Why, then, does the Gemara need to say that Rebbi Shimon prohibits the lamp because of "Huktzah l'Mitzvaso"?)

ANSWER: The ME'IRI answers that the proper text of the Gemara's conclusion is "Ho'il v'Huktzah l'Mitzvaso v'Huktzah l'Isuro" (with the "Vav"), and it means that there are indeed two different reasons to prohibit the lamp. This also appears to be the Girsa of the Ritva and Ramban (see Girsa section).

It appears that RASHI, though, had the text as it appears in our edition of the Gemara, "Ho'il v'Huktzah l'Mitzvaso Huktzah l'Isuro" (without the "Vav"). Nevertheless, Rashi understands the Gemara the same way as the Me'iri, and both reasons to prohibit moving the lamp apply. He understands that the words of the Gemara mean that "for the same amount of time that the lamp is Muktzah due to the Isur (i.e., it may not be moved because it is a "Basis l'Davar ha'Asur"), it is also Huktzah l'Mitzvaso." Accordingly, both prohibitions apply. (This is also the conclusion of the SEFAS EMES.)

QUESTION: Rebbi Yochanan was asked whether one is permitted to move a chicken's nest, or roost, on Shabbos. He answered, "It is made only for the chickens," and one may not move it.

RASHI (DH Ela l'Tarnegolin) explains that the Gemara's initial assumption is that the coop is Muktzah because it is a Kli she'Melachto l'Isur, a utensil whose primary use is for a Melachah that is forbidden on Shabbos. The conclusion of the Gemara is that the coop has an inedible egg resting in it which makes it a "Basis l'Davar ha'Asur." According to the Gemara's conclusion, why did Rebbi Yochanan say that "it is made only for the chickens"? He should have said that it is forbidden simply because it has an inedible egg in it, and thus it is forbidden whether the nest is made for chickens or not!

ANSWER: TOSFOS (DH d'Is Bei Beitzas) answers that one of the conditions of "Basis l'Davar ha'Asur" is that an object does not become a "Basis" unless a Muktzah object was placed on it intentionally. If a Muktzah object accidentally landed there, it may be shaken off and the object beneath it is not a "Basis." Therefore, had we not anticipated that an egg would be found in the nest, the nest would not have been a "Basis" and the egg could have been shaken off and the nest moved. However, since "a nest is made only for the chickens," we expect to find eggs there, and thus it is considered as though the owner placed the egg there intentionally. Therefore, the roost is a "Basis" for an object of Muktzah and may not be moved.