QUESTION: Reish Lakish asks whether one may use a Lulav that was cut from a palm tree that was worshipped as Avodah Zarah. Rav Dimi explains that his question is whether the nullification (Bitul) of Avodah Zarah that occurs when the Lulav is cut from the tree permits the Lulav to be used for a Mitzvah or not. On one hand, it should be permitted because the Lulav is no longer part of the Avodah Zarah. On the other hand, perhaps since it was once unfit to be used for the Mitzvah, it remains unfit for the Mitzvah (this is referred to as "Dichuy Etzel Mitzvos"). (The question of Reish Lakish regarding "Dichuy" applies only if the Bitul of the Avodah Zarah was done on Yom Tov, since the Lulav was not fit at the beginning of Sukos. However, if the Bitul was done before Yom Tov, then the Lulav certainly may be used for the Mitzvah. There is no question of "Dichuy" since the Lulav was fit to be used from the time that the obligation to fulfill the Mitzvah took effect. See TOSFOS DH Asheirah, and RASHI to Sukah 33b, DH Dichuy me'Ikara.)

The Gemara attempts to determine the Halachah based on a Mishnah (Chulin 87a) that discusses the Mitzvah of Kisuy ha'Dam. The Halachah is that if the wind blew sand on top of the blood of a bird that was slaughtered, one is not required to cover the blood any more. However, if the blood later becomes uncovered, then one becomes obligated to cover the blood with sand (since he never did an act of covering the blood). We see from there that even though the Mitzvah did not apply to the blood, nevertheless when the blood later becomes uncovered one is obligated to perform the Mitzvah. This shows that there is no "Dichuy Etzel Mitzvos."

How can the Gemara compare using a Lulav that was once disqualified to covering blood that was once covered? The Mitzvah of Kisuy ha'Dam is an obligation upon the person; just because the blood was once covered does not exempt the person from his obligation. Whenever the blood becomes uncovered, he must fulfill his obligation. In contrast, there is no obligation to use this particular Lulav for the Mitzvah. Therefore, this Lulav can be disqualified permanently through Dichuy without exempting the person from his obligation to hold a Lulav! In other words, Dichuy should be able to disqualify an object from a Mitzvah, but it should not be able to exempt a person from his obligation to perform a Mitzvah.

ANSWER: The ROSH (Moed Katan 3:96) writes that if a child becomes Bar Mitzvah within thirty days of the passing of one of his parents, he is obligated to observe the laws of mourning. The MAHARAM MI'ROTENBURG explains that even though the child was a Katan when the Mitzvah took effect, the rule of "Ein Dichuy Etzel Mitzvos" applies and obligates him in Avelus. The Rosh disagrees and writes that the question of Avelus is not related to the principle of "Ein Dichuy Etzel Mitzvos." "Ein Dichuy Etzel Mitzvos" applies when the object that is to be used for a Mitzvah (or the animal that is to be used as a Korban) becomes unfit, while the person's obligation is not affected. However, if the person was not obligated to fulfill the Mitzvah at the time that it took effect, then the person never becomes obligated to do that Mitzvah.

It is clear from the Rosh that the question of "Dichuy" with regard to Mitzvos and Korbanos is a question involving the object that will be used for the Mitzvah or the Korban, but it does not involve the person's obligation. The obligation of the person depends exclusively on whether the Mitzvah was applicable to him at the time that the circumstances for the Mitzvah began. If he was not fit at that time, then he remains exempt, and if he was fit, then he remains obligated.

According to this understanding, the Gemara's discussion of Dichuy with regard to Kisuy ha'Dam cannot be relating to the obligation of the Shochet to cover the blood. Since the Mitzvah applied to him at the time of Shechitah, the obligation should remain with him. The Gemara's question is whether the blood which became unfit for the Mitzvah (because it was already covered with sand) can return to its former obligation and have the Mitzvah apply to it when it becomes uncovered. If there is Dichuy for Mitzvos, then the blood should no longer be subject to the Mitzvah. Since covering other blood will not fulfill the Mitzvah to cover this blood, and this blood is unfit for the Mitzvah, the Shochet will not be required to cover the blood. Therefore, the question of Dichuy with regard to Kisuy ha'Dam is comparable to the question of Dichuy with regard to Lulav. In both cases the Gemara wants to know whether an object that became unfit for a Mitzvah can become fit once again. However, with regard to Kisuy ha'Dam, if the object does not return to its former state of being obligated for the Mitzvah, then the Shochet will automatically be exempt from covering the blood (since there is no blood to cover).

According to the Rosh, perhaps the logic of those who maintain that there is Dichuy for Mitzvos is as follows. Just as an animal becomes sanctified when it is designated to be brought as a Korban on the Mizbe'ach, all other objects of Mitzvah become "sanctified," so to speak, at the time that circumstances warrant the application of the Mitzvah. When a Korban becomes unfit to be offered, it loses a certain degree of its sanctity, its Kedushah. That Kedushah cannot be replaced, since it can come only at the original time that the animal is designated and sanctified as a Korban. Once the animal has already been sanctified, the owner cannot add sanctity to it. This is why the Korban becomes permanently disqualified according to those who maintain that there is Dichuy for a Korban. In the same manner, an object can became "sanctified" for a Mitzvah only at the time that the circumstances warrant the obligation of the Mitzvah. If the object at some later point becomes unfit for the Mitzvah, it lessens the object's Kedushah and it can no longer become fit for that Mitzvah. This is why there should be Dichuy for a Mitzvah.

(The time at which a Lulav becomes sanctified for the Mitzvah is the evening of the first day of Sukos (see Rashi to Sukah 33a, DH v'Lulav). Even though the Mitzvah cannot be performed at night, this is not considered "Dichuy," since the Mitzvah is only "Mechusar Zeman," lacking the passage of time, and not "Mechusar Ma'aseh," lacking a corrective act. See ARUCH LA'NER there.)

QUESTIONS: The Mishnah teaches that if a house was built originally for the sake of being worshipped as an Avodah Zarah, the house is Asur b'Hana'ah. The Gemara quotes Rav who teaches that when a person bows down to a house, he causes it to become prohibited. The Gemara infers from Rav's statement that if an object that was detached becomes attached to the ground, it is still considered detached with regard to the laws of Avodah Zarah.

This Gemara seems problematic. What difference does it make if the house is attached or detached to the ground? What prevents something that is attached ("Mechubar") to the ground, such as a mountain, from becoming prohibited is the fact that it has no "Tefisas Yedei Adam" -- it was never handled by human hands. For example, the Gemara earlier (46a) mentions that, according to one opinion, if a stone breaks loose from a mountain on its own, that stone does not become prohibited when it is worshipped because there is no human involvement in its creation (see Insights there). Conversely, Rebbi Yosi ha'Glili (51a) teaches that trees become prohibited when they are worshipped because they do have human involvement, "Tefisas Yedei Adam," in their formation. Therefore, whether the house is considered "Talush" (detached) or "Mechubar" (attached) should not be the subject of discussion; since the house was built by human hands, it should be subject to the laws of Avodah Zarah and it should be prohibited even if it is "Mechubar."

Moreover, why does the Gemara infer from the statement of Rav that a house is considered detached? Why does it not make that inference from the Mishnah, which says that a house that was built for Avodah Zarah becomes prohibited when worshipped?

(a) TOSFOS (45b, DH v'Hacha) explains that according to the Rabanan who argue with Rebbi Yosi ha'Glili and permit a tree that is worshipped, a tree is not considered to have been handled by a person ("Tefisas Yedei Adam"). Since it takes root after the person places it in the ground, its status changes into a piece of the ground, and it is no longer considered a tree. When it takes root, this negates any actions that were done to it before it was attached to the ground.

The Gemara infers from Rav's statement that the same reasoning does not apply to a house. When bricks are attached to the ground, they do not become part of the ground and lose their "Tefisas Yedei Adam." Rather, they retain their independent identity as bricks, and because of this the "Tefisas Yedei Adam" that they had before they were attached to the ground still applies to them now and causes them to become prohibited when worshipped.

In the final analysis, what prohibits the bricks is not the fact that they are considered detached, but the fact that they had "Tefisas Yedei Adam" which still applies to them, since their status has not changed into that of "Mechubar."

With regard to the second question, the Gemara could not prove from the Mishnah that something that was once detached and is now attached to the ground still has the status of being detached since, according to the Rabanan who argue with Rebbi Yosi, a tree does not become prohibited when worshipped after it is planted, but it does become prohibited if it is planted for the sake of Avodah Zarah. Although a tree does not have "Tefisas Yedei Adam" according to the Rabanan, there is a Gezeiras ha'Kasuv in the verse, "va'Asherehem Tisrefun ba'Esh" (Devarim 12:3; 45b), which teaches that a tree planted for the sake of Avodah Zarah becomes prohibited. The same verse teaches that a house that was built to be served as an Avodah Zarah becomes prohibited even if it is considered Mechubar.

Rav, however, teaches that the house becomes prohibited even if it was not built for Avodah Zarah. Rav's statement implies that a house is not considered Mechubar.

(b) RASHI seems to learn differently from Tosfos. Rashi (45b, DH Ilan, and 46a, DH ume'Ilan Yavesh) writes that according to the Rabanan who argue with Rebbi Yosi, a tree planted for Avodah Zarah becomes prohibited because it is considered to have "Tefisas Yedei Adam." That is, it is prohibited not because of a unique Gezeiras ha'Kasuv unrelated to the laws of Mechubar, but rather because it is in the same category of Talush, since it has "Tefisas Yedei Adam." It is evident from the Gemara's discussion of the stones that became detached from the mountain (46a) that according to those who permit stones that were detached, there is no verse that prohibits any detached object that became worshipped. Rather, the verse prohibits only objects that had "Tefisas Yedei Adam" that become worshipped, since they are not similar to mountains (which are not prohibited).

Rashi writes that according to the Rabanan, the only objects considered to have "Tefisas Yedei Adam" are objects that were initially handled (or planted) for the purpose of Avodah Zarah. The "Tefisas Yedei Adam" must be for the sake of Avodah Zarah in order to prohibit the object. What, then, is the Gemara's source that an object which is detached, such as a house, may become prohibited when it is worshipped after it has been built? Such a house was never handled for the purpose of Avodah Zarah, and thus the laws of mountains, animals, and trees should determine that such an object does not become prohibited when worshipped!

This question is especially difficult since Rashi himself (ibid.) writes that if a tree was replanted after it had already grown into a tree, it will become prohibited when it is later worshipped, since it had "Tefisas Yedei Adam" when it was replanted. Why does Rashi call the planting of a tree "Tefisas Yedei Adam"? There is only one verse that teaches the principle of "Tefisas Yedei Adam" (according to the way Rashi learns the verse), and that is the verse of "va'Asherehem Tisrefun ba'Esh" (Devarim 12:3)! If that verse is teaching that a tree planted for Avodah Zarah is prohibited because of "Tefisas Yedei Adam," then what is the source that a tree planted after it was already grown is considered "Tefisas Yedei Adam" when it was not planted for the sake of being worshipped? On the other hand, if the verse is prohibiting a tree that was planted when it was fully grown, then what is the source that a tree planted as a seed is considered "Tefisas Yedei Adam" when it was planted for the purpose of Avodah Zarah?

Perhaps one may suggest that, indeed, these two descriptions that Rashi gives for "Tefisas Yedei Adam" reflect two different, independent, and mutually exclusive approaches to the Sugya. Originally, Rashi explained the Sugya in one way, and later he retracted and chose to follow another explanation, adding the second one into his previously-written glosses while the original explanation was not removed. (See TOSFOS to 45a, DH Eloheihem, who points out that there were two conflicting versions of Rashi on the Mishnah.)

Originally, Rashi explained that the verse of "va'Asherehem Tisrefun" teaches that an object is considered to have "Tefisas Yedei Adam" only when it was handled for the sake of Avodah Zarah. According to that explanation, the question regarding the stones that broke loose from a mountain would apply to any object that was never handled for the purpose of Avodah Zarah. The opinion that permits the stones would permit such objects. The opinion that prohibits the stones maintains that a verse teaches that all detached objects become prohibited even if they were never handled by a person. (See Rashi to 46a, DH l'Hachi Kesiv.)

Accordingly, when Rav teaches that a house that was worshipped becomes prohibited even though it was not handled for the sake of Avodah Zarah, Rav must be following the opinion that prohibits stones that became detached from a mountain that were worshipped. Accordingly, this is what the Gemara means when it infers from Rav's statement that a house is considered detached. If the house would be considered attached, then it would be permitted, like a tree. However, since it is detached, a verse teaches that any detached object becomes Asur b'Hana'ah when worshipped. This answers the first question, regarding what difference it makes whether the house is considered detached or attached.

This also answers the second question. One cannot infer from the Mishnah that a house is considered detached, because the Mishnah is discussing a house that was originally built for the sake of Avodah Zarah. Something that was built or handled for the sake of Avodah Zarah becomes prohibited even if it is attached, as derived from the verse, "va'Asherehem Tisrefun."

Rashi later retracted this explanation and proposed a different explanation. The Rabanan learn from "va'Asherehem Tisrefun" not that a seed planted for the sake of Avodah Zarah is prohibited, but rather that a tree that was planted when it was already a tree and was fit for worship becomes prohibited. (This is what the Gemara means earlier (45b) when it says that "va'Asherehem Tisrefun" prohibits a tree that was "originally planted for this purpose [of Avodah Zarah]"; it was fit to be served in the state in which it existed at the time that it was planted.)

According to this explanation, it makes no difference whether a tree was planted for the sake of Avodah Zarah or not. The only crucial question is whether it was planted as a tree or as a seed.

(This also answers the questions that Tosfos asks on Rashi on 45b, DH v'Hacha.)

When a house is built, it is not attached to the ground fully built, but rather it is built brick by brick. Therefore, it is comparable to a tree that is planted as a seed. Why, then, should the house become prohibited if it was worshipped after it was built? It must be, as mentioned earlier, that Rav -- who prohibits the house -- maintains that stones which were detached from the mountain but not handled by a person become prohibited when worshipped, and only attached objects (or animals) remain permitted when worshipped. This is what the Gemara means when it infers from Rav that a house is considered a detached object -- because it becomes prohibited when worshipped. This answers the first question.

Regarding the second question -- why does the Gemara not infer this from the Mishnah -- one may suggest that had it not been for Rav's statement, we would have learned that the Mishnah follows the opinion of Rebbi Yosi ha'Glili, who considers even a tree that grew from a planted seed to be "Tefisas Yedei Adam." Rav, however, certainly rules like the Rabanan who argue with Rebbi Yosi ha'Glili. When he prohibits a house that was worshipped, it can only be because it is considered detached, and something detached is prohibited when worshipped even when it was never handled by a person. Accordingly, the prohibition of the Mishnah is also because a house is considered detached, according to Rav. This might be why Rashi in Sanhedrin (47b, DH b'Kever Binyan) writes that a house built for the purpose of Avodah Zarah is prohibited because it was originally detached and thus is still considered detached, and not because it was originally built for Avodah Zarah (see BINYAN SHLOMO here).

(It must be noted that our explanation of the opinions of Rebbi Yosi ha'Glili and the Rabanan follows the interpretation of the argument offered by the Gemara earlier (45b). The Gemara later (48a), however, offers an entirely different interpretation of their argument.)

OPINIONS: The Gemara discusses whether an object that was attached to the ground that was worshipped as Avodah Zarah may be used for purposes of Hekdesh ("Gavoha"). The Gemara concludes that it is prohibited. In addition, the Gemara states that a house, the stones of which were once detached from the ground, is considered detached, and thus a house that was used for idol-worship should be prohibited even for non-"Gavoha" purposes.

According to this, is one permitted to make a synagogue out of a building that was used as a house of prayer by Nochrim?

(a) The MAGEN AVRAHAM (cited by the Mishnah Berurah OC 154:45) rules that one is permitted to convert a Nochri house of worship into a synagogue. Since the worshippers do not worship the house itself, the house itself is not an object of Avodah Zarah and is not prohibited.

(b) However, the Mishnah Berurah cites the ELIYAH RABAH who advises not to make such a house into a permanent Beis ha'Keneses, presumably because it is not respectful to pray to Hash-m in a house that once served such a purpose.