Nehemiah 8:15-16

15He had said that a proclamation should be made throughout their towns and in Jerusalem, telling the people to go to the hills to get branches from olive, wild olive, myrtle, palm, and other leafy trees. They were to use these branches to make shelters in which they would live during the festival, as prescribed in the Law.

16So 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.