Q. Why does Sukkot come so soon after Yom Kippur?A. There is a contrast between the more austere, solemn mood of Rosh HaShanah and Yom Kippur, and the celebratory feeling of Sukkot, “Our Season of Rejoicing”.
More than calendrical co-incidence links this series of festivals: the Kotzker Rabbi (19th cent) used to say, “Joyfulness is the outcome of holiness”, and the joy of Sukkot is the spontaneous expression of the soul that has come close to God and is at one with Him.
It is on the Biblical command, “And you shall be extremely joyful” (Deut. 16:15) that the name z’man simchatenu, “Our Season of Rejoicing”, found frequently in the prayer-book, is based.
In the Bible the festival is called Chag HaSukkot – “The Feast of Tabernacles” (Lev 23:24 etc.), Chag Ha’Asif – “The Feast of Ingathering” (Ex. 23:16 etc.), “Chag HaShem – “The Feast of the Lord” (Lev. 23:29) and simply HeChag – “The Festival” (I Kings 8:2, etc.).
Of all the festivals this is the one most often referred to in the Bible, and it must have been the one on which most people came to Jerusalem, for when the Mishnah calls it HeChag, it seems quite clear which festival is meant.