What does Nehemiah 5:13 mean?

Then I shook out the folds of my robe and said, 'This is what God will do to anyone who doesn’t keep this promise—he’ll shake them out and leave them with nothing.' Everyone there said, 'Amen,' and praised the Lord. The people did what they promised. Nehemiah 5:13 - Modern Text Bible

(Nehemiah uses a symbolic gesture to warn of consequences for breaking the oath. The people agree and follow through.)