“Then the king of Assyria sent.” Sennacherib, the king of Assyria had accepted the gold and silver from Hezekiah (2 Kings 18:14-16), but did not withdraw as he had apparently promised, but instead attacked Jerusalem. Sennacherib was ruthless and a liar. Hezekiah knew that surrender to him meant the deportation of the people to foreign lands, as Assyria had already done to Israel, and Hezekiah was desperate that that did not happen.
“the highway of the Launderer’s Field.” That is, the highway by the field where cloth is washed and dried. Although many versions say “fuller’s field,” is it not well known today that a person who washed clothing used to be called a “fuller.” This was the place where Isaiah had met Ahaz some years before and told Ahaz to ask for a sign from God that Judah would be delivered (Isa. 7:3), but Ahaz would not ask for a sign because he had already hired the Assyrians to attack Syria and Israel. Now that evil tactic bore evil fruit and the Assyrians were back.