During the seven days of succos we
offer 70 bulls as korbanos corresponding to the seventy nations. On Shmini
Atzeres the theme is [as we discussed in a previous post] "nismach Ani
vi-atem" – an intimate day where it is just us and Hashem. All that is
left is the Jewish people who are the highest and most pure expression of what
man is supposed to be [when we behave ourselves…], as the gemara puts it -
אתם קרויים אדם.
This sheds light on why Shmini
Atzeres is the day of rain "Yom Hgshamim". The appearance of rain in
the world was tied up with the creation of man "lo himteer .. vi-adam
ayin" – there was no rain until man was in existence to show his
appreciation [Breishis 2/5]. Shmini Atzeres is the time when the ideal
expression of man is the "star of the show" and Klal Yisrael is alone
kviyachol with Hashem. It makes complete sense then that it is the "Yom
Hagshamim".