Adam Clarke's Commentary on the Bible - Isaiah 8:8
He shall reach even to the neck - He compares Jerusalem, says Kimchi, to the head of the human body. As when the waters come up to a man's neck, he is very near drowning, (for a little increase of them would go over his head), so the king of Assyria coming up to Jerusalem was like a flood reaching to the neck - the whole country was overflowed, and the capital was in imminent danger. Accordingly the Chaldee renders reaching to the neck by reaching to Jerusalem. read more
Adam Clarke's Commentary on the Bible - Isaiah 8:6
Forasmuch as this people refuseth "Because this people have rejected" - The gentle waters of Shiloah, a small fountain and brook just without Jerusalem, which supplied a pool within the city for the use of the inhabitants, is an apt emblem of the state of the kingdom and house of David, much reduced in its apparent strength, yet supported by the blessing of God; and is finely contrasted with the waters of the Euphrates, great, rapid, and impetuous; the image of the Babylonian empire, which... read more