Albert Barnes Commentary 2 Kings 19:23

"By thy messengers thou hast defied the Lord, and hast said, With the multitude of my chariots am I come up to the height of the mountains, to the innermost parts of Lebanon; and I will cut down the tall cedars thereof, and the choice fir-trees thereof; and I will enter into his farthest lodging-place, the forest of his fruitful field." — 2 Kings 19:23 (ASV)

And you have said - Isaiah puts into words the thoughts of Sennacherib’s heart—thoughts of the most extreme self-confidence. (Compare Isaiah 10:7-14, where, probably at an earlier date, the same overweening pride is ascribed to this king.)

With the multitude of my chariots - There are two textual readings here, which have nearly the same meaning. The more difficult and poetic of the two is to be preferred. A literal translation of it reads, With chariots upon chariots I have come up...

To the sides of Lebanon - Lebanon, with its cedars and fir trees, should be understood here both literally and figuratively. Literally, hewing timber in Lebanon was a common feature of an Assyrian expedition into Syria. Figuratively, the mountain represents the most inaccessible parts of Palestine, and the destruction of its firs and cedars signifies the complete devastation of the entire country from one end to the other.

The lodgings of his borders - This literally means “the lodge of its (Lebanon’s) end.” This could refer to an actual dwelling located on the highest point of the mountain range, or it could be a poetic expression for the highest point itself.

The forest of his Carmel - This can also be read as “the forest of its garden,” that is, “its forest which is like a garden.”