From the first day of shemini ‘atseret (Oct. 5th 2015) we began reciting the prayer mashib haruah umorid hageshem, i.e., HaShem “makes the wind blow, and He makes the rain descend [on the earth]”. With these words we acknowledge that God is the One Who controls the weather system which, among other things, produces rain.
In this prayer we are not “asking” God for rain. We are rather expressing our appreciation for His power to make rain.
The prayer in which we request rain barekh ‘alenu is going to be said later on. But why aren’t we asking for rain now, at the beginning of the autumn season, when rain is expected and most needed in Israel?
The answer is simple and inspiring. In ancient Israel the Jews came walking to celebrate Sukkot in Jerusalem, from very distant places. After shemini ‘atseret every one would come back home. The Rabbis observed that the farthest cities from where the pilgrims came from, were close to the Euphrates river . And they calculated that it would take up to two weeks to walk back to those towns. The Rabbis did not see with good eyes that a Jew in Jerusalem would be asking God for rain, knowing that some of his brothers are still walking back home, and for them rain will not be a blessing at this time. The Rabbis established then that the prayer for rain should be said two weeks after Sukkot. To give everyone the opportunity to be back home safe and sound.
This is why in Erets Israel, even in our days, the blessing barekh alenu is not said until the 7th of Heshvan, exactly two weeks after shemini ‘atseret.
This halakhic rule teaches us a lesson which goes beyond the specific prayer for rain. Sometimes we might be praying to God for something that would be good for us but bad for somebody else. This is one the main reason that we always pray in plural. For example: in the prayer where we ask God for our livelihood (parnasa) we do not say: “bless me”. We always say: “bless us”. I ask God to bless me and my next door competitor, the one that sells the same merchandise, to the same customers I sell to. Our belief is that HaShem’s blessing in infinite, and He does not need to take from someone else to give me. Praying in plural reinforces our kindness and sensitivity for others.
This idea, by the way, is very similar to the win/win mentality in modern marketing, as opposed to the old win/lose mentality.