Does divorce occur with the statement: "By Allah, if you don't keep quiet tonight, I will divorce you right now," after a heated argument with the wife? And does it occur if she remained silent after the statement and then the argument resumed? If it does occur, what is the method of returning?

This confirmed oath does not result in divorce. However, you are liable for an expiation for breaking an oath if you violate it. The violation depends on your intention when you swore the oath. If you intended to prevent her from speaking on a specific night, and she spoke on that night, and you did not divorce her, then you have broken the oath, and expiation is due. If, however, you intended to prevent her from speaking for a certain period or about a specific matter, and she complied, then her speaking in another context does not constitute a violation, because intention in an oath specifies the general and restricts the absolute. If you pronounced a revocable divorce, you may take your wife back before the expiry of her iddah.