Ezekiel 4:2-3

And lay siege against it, and build forts, and cast up a mount, and set a camp against it, and place battering rams round about it.

And take unto thee an iron pan, and set it for a wall of iron between thee and the city: and set thy face resolutely against it, and it shall be besieged, and thou shalt lay siege against it: it is a sign to the house of Israel.