What is "Bikurei K'tzir Chitim" referring to? Why are they called by that name?
Rashi #1: It refers to the Sh'tei ha'Lechem on Shavu'os, so-called because they comprise the first Minchah that is brought from that year's wheat harvest. 1
Rashi #2 (in Rosh Hashanah, 16a): It refers to the Bikurim, which may only be brought from Shavu'os and onwards.
Bearing in mind that the Omer on Pesach is from barley (Rashi).
Why does the Torah call Succos "Chag ha'Asif"?
Rashi: Because it corresponds to the ingathering of the crops - from the field into the house.
What is the meaning of "Tekufas ha'Shanah"?
Rashi: It means when the new year comes around (at the beginning of the year).
What is the significance of the term "Tekufas ha'Shanah"?
Sanhedrin, 13a: It refers to the winter solstice, and it teaches us that the whole of Sukos must take place in the winter solstice - Consequently, if the winter solstice falls even one day after the fifteenth of Tishri, the Sanhedrin will declare a leap-year. 1
This is the opinion of R. Yehudah. See Torah Temimah, note 33, who explains the isuue in detail.
