In the seventh aliyah we read about the holiday of Succos with a different order of offering for each day. On the first day 13 bulls, 12 the second day, and so on, 1 less each day for a total of 70 bulls offered. Rashi says that the 70 bulls refer to the 70 non-Jewish nations, and during the times of the Temple, these offerings of 70 bulls protected the 70 nations from afflictions. Yet those same nations didn't appreciate that fact and destroyed the Temple.
Following the description of Succos, this aliyah discusses the holiday of Shemini Atzereth. This is the last holiday in the yearly chronological sequence of holidays. And Rashi says this is like a father whose children are about to leave. He says to them: please stay one more day with me. And that's what Shemini Atzereth is like: one more day together with G-d at the end of all the other holidays.
