Ezekiel was asked by god 7 days after he received his call to prophecy to completely mute himself unless it was god’s sayings that he said. It was also said that the dumbness would last until the fall of the city. After seven and a half years, when news came of the city’s fall, he could finally speak and was not dumb anymore.
This is written in the book f Ezekiel and is visible for anyone who wishes to read it for themselves. It is important to understand the different aspects of the book in order to know the whole story and the meaning behind the different actions of god.