In the days of Ezra and Nehemiah (Nehemiah 8) there was a great reformation of true religion as over 42,000 returned exiles worshipped the God of Israel in Jerusalem. They kept the feast of Tabernacles in the 7th month for eight days from the 15th day onwards.
It was a harvest feast and commemorated their pilgrimage through the wilderness when both they and the ark of God dwelt in tents.
As with every Jewish feast it pointed to Christ. John 1:14 literally reads that God incarnate dwelt among us “tabernacled” among us. Many believe Christ was born at this season of the year, NOT Xmas!
A sukkah or booth.
The feast also has a future fulfilment in the great ingathering of God’s elect people at the end of the world, many believe the second coming will be at tabernacles season, when he will usher in eternity, and God in Christ will forever tabernacle with his people, he and his church will be one at the great marriage supper of the lamb (and interestingly many Jewish weddings are held under a sukkah).