Sukkot (Tabernacles)

From the 15th to the 21st of the seventh month, Israel dwells in booths (sukkot) to remember that YHVH made them dwell in booths when He brought them out of Egypt — and that He Himself dwelt in the midst of the camp. It is the feast of the gathered harvest and of commanded joy: "you shall rejoice before YHVH your God seven days."

John 1:14 uses exactly this image of Messiah: "And the Word became flesh and dwelt (eskēnōsen: pitched His tent, His sukkah) among us." And Zechariah 14:16 carries the feast into the future: the remaining nations will go up year after year to Jerusalem "to celebrate the Feast of Tabernacles."

It is the only autumn feast with an explicit command to rejoice — the goal of the whole calendar: God dwelling with mankind (Revelation 21:3).