Forty Days at the Kotel
There is a somewhat widespread belief that praying at the Kotel for forty consecutive days is an effective segula for ensuring that one's prayers and requests will be answered. There are a number of other segulot which are based on a forty day sequence, as well. Among them are: reciting the entire book of Tehillim every day for forty days, reciting Shir Hashirim every day for forty days, and guarding one's mouth from lashon hara for forty days.
It is also related that Rabbi Elazar Mendel of Lelov would advise those who would come to him in search of Divine healing and salvation to eat a good breakfast every morning for forty days straight.[1] It once happened that a certain chassid who received this advice from the Lelover Rebbe did so for about 37 days but then neglected to complete the remaining three days because he had been feeling better. The illness quickly returned, however, propelling the chassid back to his Rebbe, explaining to him what had transpired. The Rebbe told him that he would now be required to begin the forty days of breakfast anew if he truly desired to rid himself of his illness permanently – and so it was. The forty day "breakfast segula" is actually one which has been prescribed by other Rebbes as well for a number of different problems requiring Divine intervention.
It is unclear, however, what the basis or credibility of these "forty-day" segulot truly are. It is suggested that one of the sources for the idea of praying for something for forty days straight derives from Noach. The Torah tells us that Noach first opened the window of the ark in order to see what the world looked like "forty days" after the waters of the flood had ceased. Some commentators suggest that it was actually God who opened the window in response to Noach, who had been praying for such - for the previous forty days.[2]
Another precedent for praying for something for forty days straight derives from Moshe. The Torah tells us that Moshe prayed to God that He forgive the Jewish people for having worshipped the Golden Calf. His prayers were answered after forty days.[3] Based on Moshe's precedent and experience, our sages advise us not to pray for a single request for longer than forty days. It is taught that if God desires to grant a request, He will do so within a forty day period.[4]
Although there are a number of precedents for a segula of forty days of continuous prayer, there does not seem to be any classical source which points specifically to the Kotel as the station for it. The emergence of the Kotel as the focus for the segula of forty consecutive days of prayer is likely only of recent vintage, when visiting the Kotel had become easier then ever before in 1967. It is reported that the somewhat mystical Rabbi Yisroel Yaakov Fischer was among those who subscribed to this segula and advised people in need to pray at the Kotel for forty consecutive days. In contrast, Rabbi Yosef Shalom Elyashiv doubts the authenticy of this segula. [5]
It may just be that it is not the Kotel which is the strategic component of this segula, but rather, it is the added merit of performing the forty days of prayer at a holy site. We are taught that praying at a holy site contributes to the efficacy of one's prayers and the increases the chances of them being answered. One who desires to have a go at this segula but is unable to travel to the Kotel for forty consecutive days can substitute the Kotel for any holy site, such as a synagogue or the tomb of a righteous individual.
[1] Segulot Habesht;Pat Shacharit
[2] Beit Aharon (Karlin);Noach
[3] Devarim 9:18
[4] Sifri Behalotecha 47
[5] See: http://lifeinisrael.blogspot.com/2009/11/interesting-psak-form-rav-elyashiv-40.html