In Ezra 3, we read about the people of Israel gathering at the Water Gate to rebuild the temple altar. In Nehemiah 8, a similar gathering occurs, but for a different reason: the people wanted Ezra to read the Book of the Law to them. Instead of reform coming from the top down, this time it came up from the people. With the completion of the city wall, the people of Israel were thankful to the Lord. They wanted to keep the feasts of thanksgiving and the new moon festivals, but they needed to be instructed from the Book of Moses. The people wanted to be sure that their worship was pleasing to the Lord and done according to His will.
At the beginning of Nehemiah 8, only four or five days had passed since the people completed rebuilding the wall around Jerusalem. With its completion, the people were eager to hear the Word of the Lord and to give Him thanks. The people gathered together around the Word of God.