Nehemiah 8:13-18 NIV
On the second day of the month, the heads of all the families, along with the priests and the Levites, gathered around Ezra the teacher to give attention to the words of the Law. They found written in the Law, which the LORD had commanded through Moses, that the Israelites were to live in temporary shelters during the festival of the seventh month and that they should proclaim this word and spread it throughout their towns and in Jerusalem: “Go out into the hill country and bring back branches from olive and wild olive trees, and from myrtles, palms and shade trees, to make temporary shelters”—as it is written.
So the people went out and brought back branches and built themselves temporary shelters on their own roofs, in their courtyards, in the courts of the house of God and in the square by the Water Gate and the one by the Gate of Ephraim. The whole company that had returned from exile built temporary shelters and lived in them. From the days of Joshua son of Nun until that day, the Israelites had not celebrated it like this. And their joy was very great.
Day after day, from the first day to the last, Ezra read from the Book of the Law of God. They celebrated the festival for seven days, and on the eighth day, in accordance with the regulation, there was an assembly.
NIV: New International Version