The Talmudic tradition that there are seventy nations in the world is based on the list of Noah's descendants<ref>R' Bachya</ref>. This tradition of seventy nations is deep-rooted. According to the Midrash each of the seventy nations is placed under the protection of a special angleangel, except Israel, whose Protector is G-d Himself.<ref>Genesis Rabbah 37</ref>
The seventy bullocks sacrificed on Tabernacles were offered to atone for the seventy nations. 'Woe to the nations!' says Rav Yochanan; 'for they suffered a loss [by having destroyed the Temple] and do not realize the extent of the loss. While the Temple existed the altar [the sacrifices] atoned for them, but now [that it is destroyed] who will atone for them?'<ref>Sukkah 55b, Pesikk. 193b, 195b</ref>
