Whose arrows are sharp, and all their bows bent, their horses' hoofs shall be counted like flint, and their wheels like a whirlwind:
All their bows bent - ready for battle.
Their horses' hoofs ... flint. The ancients did not shoe their horses; hence, the value of hard hoofs for long marches.
Their wheels - the wheels of their chariots. The Assyrian army abounded in cavalry and chariots (Isaiah 22:6-7; Isaiah 36:8).