When the Jewish people committed the sin of the Golden Calf, Moses tried to repent on their behalf before God. It was only after dwelling for 40 days up in Heaven and praying for forgiveness, that God accepted the apology and yield to his prayer.
It is from this incident that the term 40 days of prayer has gotten its meaning.
In the Jewish tradition it is well known that prayers for 40 consecutive days have great power. Furthermore it is even more powerful when these prayers take place at the Western Wall, the holiest place on earth, where prayers from all over the world gather to ascend to Heaven.
There are many stories of people whose prayers were miraculously answered and lives dramatically changed after the completion of 40 days of prayer at the Western Wall.
This task of coming to the Western Wall for 40 consecutive days, day in day out, is not as simple as it sounds. A person must be totally committed to this mission and must be persistent regardless of whether it’s a workday or holiday or even Shabbat when one has to walk the whole way to the Wall (since driving on Shabbat is forbidden by the Torah law). The commitment also necessitates going to the Western Wall in all sorts of weather, be it in the hot sun or freezing cold rain or storm. You cannot skip a day!
This total commitment, combined with the fact that a person is willing to clear his schedule every day, for 40 consecutive days, in order to focus on prayers and on his relationship with God, are probably part of the secret of why this spiritual ritual (segula) is, in fact, a success.
Although it is preferable for a person to perform this segula on his own, there is also the option of having someone else pray on your behalf at the Western Wall for 40 consecutive days. This option is usually best for people who live out of Jerusalem and are not able to come every day. People from all around the world who have heard of the great power of this segula have already taken advantage of this opportunity and have sent a messenger to pray on their behalf at the Western Wall for 40 days. Many of their prayers have already been answered.