The Netziv on Sukkos

The Netziv, in Harchev Davar, says that on Sukkos, all the nations of the world would gather in Jerusalem to celebrate the festival and pray for the rains.

They did this in the days of Dovid and Shlomo and will do so again when Moshiach is here. The nations were also there when Shlomo spoke his words of Koheles, and it is for this reason that the name of G-d, "Elokim," is used exclusively in it, for they do not know more of Him.

Only Klal Yisrael merits knowing G-d's name of mercy, His attribute of "Hashem."