Spear - Properly, a javelin for hurling at the enemy (see 1 Samuel 17:6 note): an ordinary weapon of the Babylonians.
Cruel - ruthless, inhuman. In the Assyrian monuments warriors put the vanquished to death; rows of impaled victims hang round the walls of the besieged towns; and men collect in heaps hands cut from the vanquished.
Horses, set in array - A full stop should be put after horses. It - the whole army, and not the cavalry only - is “set in array.”
As men for war against thee - Rather, as a warrior for battle “against thee.”