And lay siege against it, and build a fort against it, and cast a mount against it; set the camp also against it, and set battering rams against it round about.
Build a fort against it - rather, a watch-tower (Jeremiah 52:4) wherein the besiegers could watch the movements of the Besieged (Gesenius). A wall of circumvallation (The Septuagint and Rosenmuller). A kind of battering-ram Maurer). The first view is best.
A mount - wherewith the Chaldeans could be defended from missiles.
Battering-rams - literally, through-borers. In Ezekiel 21:22 the same Hebrew is translated "captains."