In the march 1986 issue of the jewish observer, they bring bamidbar rabbah 21 which says in the name of Yehoshua ben levi, “Hoshana rabba represents the ultimate downfall of defiant nations, just as the entire Succos festival represents their progressive slide from dominance, as is symbolized by the reduction in the number of daily mussaf sacrifices offered on their behalf.” However, i could not find this in the soncino translation. Did they censor this out, is it in the original Hebrew edition of bamidbar rabbah?
I looked at the twenty mentions of יְהוֹשֻׁעַ בֶּן לֵוִי in the Sefaria text of Bamidbar Rabba and didn't see anything which mentioned Hoshana Rabbah or Sukkot or musaf sefaria.org/Bamidbar_Rabbah.1.3?lang=bi– rosendsMar 7, 2019 at 20:08
To hunt this down, try this reference "Bamidbar Rabbah 21: for an extensive treatment, see Overview by Rabbi Nasson Scherman on the Hoshana Prayerb)! Artscroll Menorah Serles. p. xxxvi"– rosendsMar 7, 2019 at 20:17