WHAT IS THE REASON PEOPLE PRAY BY ROCHEL IMENU KEVER FOR 40 DAYS?
The concept of 40 days of prayer is found in the Torah when Moshe begged for 40 days that God should forgive the sin of the golden calf, and afterwards 40 days to prepare for the 2nd giving of the Ten Commandments. The numerical value (gematriya) of the Hebrew letter mem, written as “mayim” [=water] is 40, as is the amount of water necessary for purification in the mikveh (40 sa’ah) as well as in the purification basin in the mishkan and in the Holy Temple (40 batt). This is because water symbolizes life which is the anti-thesis of death [=tum’ah], so purification is achieved through 40 [mem=mayim=water] X 40. After undergoing purification, it’s as if one is “born again” [thus, we enter the mikveh as we were in the womb- no clothing, nail-polish, earrings, etc. and in the fetal position] and we get a new start in life. Accordingly, whenever the number 40 appears in the Tanach, it’s referring to being “born again”, a new start after achieving forgiveness. When Noach’s generation sinned, their punishment was 40 days of flood, and only then, did the world get a new start. The 40 years in the desert atoned for the sin of the spies, and 40 lashes atoned for sins in the Sanhedrin. Jonah gave Nineveh 40 days to repent and get a new start, as there are 40 days of t’shuva [Ellul+ 10 days of repentance] every year. Similarly, a fetus is halachically considered a life only after 40 days, and Hashem created human pregnancy to last 40 weeks= the start of life. In short, there's a special effect if we pray to God at holy sites for 40 days, to judge us favorably based upon our spiritual rejuvenation, forgiving us and “wiping our slate clean” to be “born again” and be given another chance. But even 1 sincere prayer, even in the comfort of your own home and in your own language and words, is significant and can effectively help and strengthen your connection to God, especially if you resolve to "turn over a new leaf" and earnestly improve (as we all can always improve)! All the best and Shabbat Shalom!