41 And you, son of man, take a back and put it before you and on it make a picture of a town, even Jerusalem. 2 And make an attack on it, shutting it in, building strong places against it, and making high an earthwork against it; and put up tents against it, placing engines all round it for smashing down its walls. 3 And take a flat iron plate, and put it for a wall of iron between you and the town: and let your face be turned to it, and it will be shut in and you will make an attack on it. This will be a sign to the children of Israel.
Matthew Henry's Commentary on Ezekiel 4:1-3
Commentary on Ezekiel 4:1-8
(Read Ezekiel 4:1-8)
The prophet was to represent the siege of Jerusalem by signs. He was to lie on his left side for a number of days, supposed to be equal to the years from the establishment of idolatry. All that the prophet sets before the children of his people, about the destruction of Jerusalem, is to show that sin is the provoking cause of the ruin of that once flourishing city.