This means the he will hold one of the articles of his divination that was read as a divination against Jerusalem in his right hand. Alternate translation: "In his right hand will be an article of divination with an omen against Jerusalem" (See: [[rc://en/ta/man/jit/figs-metonymy]])
A battering ram was a cut tree or large log with a sharpened end or an end covered in metal. It was held by several men who would pound the end against a wall.
# to build a ramp
These were large dirt ramps that the Babylonian soldiers built so that they could get onto the walls of Jerusalem.
# siege towers
These were wooden towers that the Babylonian soldiers built around Jerusalem to enable them to shoot arrows over the walls of Jerusalem.