1) HALACHAH: PLACING NOTES IN THE KOSEL HA'MA'ARAVI
QUESTION: The Mishnah (85b) states that the thickness of the walls ("Ovi ha'Chomah") around Har ha'Bayis was sanctified with the Kedushah of Har ha'Bayis. If the walls have Kedushah, may one put his hand or place notes ("Kvitlach") in the crevices of the Kosel, the western wall of Har ha'Bayis?
(a) It is clear from the Gemara that the area upon which the wall stands indeed has Kedushah. For this reason, the entranceways of the gates that lead into Har ha'Bayis are sanctified. Nevertheless, the Gemara concludes that the reason the gates are sanctified is because they are on ground level. The windows and the top of the wall are not sanctified, because they are not on ground level. When the Mishnah says that they have Kedushah, it refers to windows in the wall that are level with the ground of the Azarah, and to low walls, the tops of which are level with the ground of the Azarah.
According to the straightforward understanding of the Gemara, there should be no problem with placing one's hand or a note into a crevice in the Kosel.
(b) However, the RAMBAM (Hilchos Beis ha'Bechirah 6:9) rules that the windows and the thickness of the walls are sanctified, in contrast to the conclusion of the Gemara.
The RA'AVAD qualifies the Rambam's ruling and writes that the windows and the top of the walls have Kedushah only where they are level with the ground of the Azarah. The KESEF MISHNEH suggests that perhaps this is also the intention of the Rambam. However, there is no indication to that effect in the words of the Rambam. The Rambam mentions this Halachah elsewhere (see, for example, Hilchos Korban Pesach 9:1), but he never mentions that it applies only to windows and the parts of the thickness of the walls that are level with the ground.
Moreover, the Rambam himself rules that the roofs and upper stories ("Gagin v'Aliyos") do not have Kedushah (Hilchos Beis ha'Bechirah 6:7). How can the Rambam rule that the top of the wall is considered like the inside of the wall and is sanctified, and the roofs -- which are situated inside the Azarah -- are like the outside and are not sanctified?
The RADVAZ explains that the Rambam's source is the Gemara in Zevachim (56a) which appears to argue with the conclusion of the Gemara here. The Gemara there understands the Mishnah literally, that the windows and the top of the walls are like the inside and are sanctified, even when they are not level with the ground. This is also the approach of the CHAFETZ CHAIM (in ZEVACH TODAH).
What, though, is the difference between the roofs and the top of the walls? Perhaps the difference is based on whether the area is considered a primary place of usage. The primary places of usage on a wall are the top of the wall and the windows in the wall. Roofs and upper floors, however, are not the primary places of usage of a structure. Rather, the room or chamber underneath the roof is the primary place of usage. The roofs and upper floors are only secondary uses of the structure. Therefore, they are not sanctified. Only areas which are the primary places of use are sanctified.
According to the Rambam, if there would be windows in the Kosel, they would be sanctified with Kedushas ha'Azarah, and a person who is Tamei (such as a Nidah or Ba'al Keri) would not be allowed to walk on the top of the wall or to put his hand in a window in the wall. However, one should still be permitted to place his hand in the crevices in the Kosel. Since the crevices do not penetrate the entire thickness of the Kosel, they should be no different from chambers in the Azarah which open only into non-sanctified areas. The Gemara says that such chambers are not sanctified.
HALACHAH: According to the above considerations, one should be permitted to place notes in the Kosel, even according to the Rambam. However, RAV OVADYAH YOSEF (in YABI'A OMER 5, YD 27:2) points out that there might be another problem. As the height of the Kosel increases, its thickness narrows, because each layer of stone is slightly recessed from the one beneath it (this was an architectural technique that was designed to maximize a wall's strength and stability). Consequently, when one stands immediately next to the Kosel, he is actually standing on top of the wall; he is standing directly above the wall's lower layers of stone. For this reason, a person who is Tamei should be prohibited from walking within a meter or two of the Kosel.
In practice, however, Rav Ovadyah Yosef does not rule that one may not approach the Kosel. Perhaps the reasoning expressed above applies here as well -- the recessions of the wall should be no different from chambers in the Azarah which open into non-sanctified areas. Since there is still a Mechitzah (the rest of the Kosel) that separates between the person and Har ha'Bayis, the area above each layer of stone opens into an area outside of Har ha'Bayis, and therefore the area above the wall should be considered to have no Kedushah.
Nevertheless, it has been said that some of the great sages of Yerushalayim had the practice not to walk right next to the Kosel. (This is not the practice of most people today. See also IGROS MOSHE, end of OC 2:113.)
2) EVERYTHING THE HOST TELLS YOU TO DO, YOU MUST DO
OPINIONS: Rav Huna brei d'Rav Nasan visited the home of Rav Nachman bar Yitzchak. The hosts told Rav Huna to recline, and he did so. When they asked him why he reclined, he answered, "Everything the host tells you to do, you must do, except for 'leave' (Chutz mi'Tzei)."
What does "Chutz mi'Tzei" mean? If the host tells his guest to leave, why should the guest not listen to him? It is certainly indecorous to remain in someone's home when requested to leave. (In fact, the ME'IRI writes that some "Letzanim" (jokers) added this phrase to the Gemara, and it should be omitted).
(a) The MAGEN AVRAHAM cites the BACH who says that a guest does not have to comply with his host's word when his host tells him to go to the market to buy something for him. The host does not have the prerogative to send his guest out of the house to do errands for him.
The MAHARSHA adds that a guest is required to listen to his host only inside of the host's home, where the owner of the house serves in the capacity as host. Once the host asks his guest to go out of the house and do things for him, he is no longer the host.
(b) The SEFAS EMES says that perhaps this phrase was added to the Gemara because of the incident of "Kamtza and Bar Kamtza" (Gitin 56b). Bar Kamtza suffered immense embarrassment when the host insisted that he leave his home, and he took vicious revenge which ultimately resulted in the destruction of the Beis ha'Mikdash. After the Churban, the Chachamim added to the dictum, "Everything the host tells you to do, you must do," the condition "except for 'leave'." If the host attempts to embarrass the guest and insists that the guest do something humiliating, the guest does not have to listen to him.
(c) Some explain that this dictum alludes to one's service of Hash-m. The Gemara in Chagigah (15a) relates that after Elisha ben Avuyah, also known as "Acher," turned from the path of Hash-m, he heard a heavenly message proclaim, "Return in repentance, wayward children -- except for Acher!" When he heard this, he despaired of doing Teshuvah and he became a sinner. He should not have listened to the heavenly message, because the gates of Teshuvah are never closed to anyone. The statement, "Everything the host tells you to do, you must do, except for 'leave'," means that whatever the Ba'al ha'Bayis -- Hash-m -- tells you to do, you must do, except for "leave." If one hears a heavenly message proclaim that he must leave the service of Hash-m because his Teshuvah will not be accepted, he must not listen, because Hash-m always accepts a person's Teshuvah. (REISHIS CHOCHMAH)