The people gather to hear God鈥檚 Word read aloud. Books would have been rare, so this was the only way most people could hear the Bible firsthand. What was being read was also explained to the people. They came to realize there was a holiday coming up called the Feast of Shelters, so it was perfect timing for them to celebrate.
This story gives a perfect example of how we should be using the Bible. First, we read and understand what it says; second, realize we haven鈥檛 done what we should be doing; and third, change direction and start doing what God says.