They got back the Book of the Law. As a nation they gathered and listened to the instructions of God's Word. There were likely tears and regret as they were confronted with the realities of things they have done wrong. There was also hope and joy in realizing that God forgives and His Word still stands. Honestly for them exile came because they did not listen to and obey God's Word. They went their own way and brought idols into their worship. If they want to stay in the land they better take these words to heart and not stray from them. They are getting back on track and God's Word is bringing them back onto the right path. When we get off track in our walk with the LORD the best thing we can do is get back into the WORD and reset ourselves back into the ways of the LORD. The quicker we return to God's commands the better off we are.