Charles Ellicott Commentary Isaiah 22:7

"And it came to pass, that thy choicest valleys were full of chariots, and the horsemen set themselves in array at the gate." — Isaiah 22:7 (ASV)

That thy choicest valleys ... —These were the valleys of Gibeon, Rephaim, Hinnom, and Jehoshaphat, which encircled Jerusalem on the west and south. They are painted as filled with the chariots and cavalry of the Assyrian army, ready to make their attack on the very gate of the city, the “great gate” named in Sennacherib’s inscription (Records of the Past, i. 39).