"Son of man, get a clay tablet. Put it in front of you. Draw the city of Jerusalem on it.
Then pretend to surround it and attack it. Make some little models of war machines. Build a ramp up to it. Set camps up around it. Surround it with models of logs to be used for knocking down its gates.
Then get an iron pan. Put it between you and the city. Pretend it is an iron wall. Turn your face toward the city. It will be under attack when you begin to attack it. That will show the people of Israel what is going to happen to Jerusalem.