On October 9 the family leaders and the priests and Levites met with Ezra to go over the law in greater detail.
References for Nehemiah 8:13
As they studied the law, they discovered that the LORD had commanded through Moses that the Israelites should live in shelters during the festival to be held that month.
References for Nehemiah 8:14
He had said that a proclamation should be made throughout their towns and especially in Jerusalem, telling the people to go to the hills to get branches from olive, wild olive, myrtle, palm, and fig trees. They were to use these branches to make shelters in which they would live during the festival, as it was prescribed in the law.
So the people went out and cut branches and used them to build shelters on the roofs of their houses, in their courtyards, in the courtyards of God's Temple, or in the squares just inside the Water Gate and the Ephraim Gate.
So everyone who had returned from captivity lived in these shelters for the seven days of the festival, and everyone was filled with great joy! The Israelites had not celebrated this way since the days of Joshua son of Nun.
Ezra read from the Book of the Law of God on each of the seven days of the festival. Then on October 15 they held a solemn assembly, as the law of Moses required.
References for Nehemiah 8:18