When Hezekiah had heard from his counsellors the report of Rabshakeh's words, he rent his clothes with horror at his daring mockery of the living God (2Ki 19:4), put on mourning clothes as a sign of the trouble of his soul and went into the temple, and at the same time sent Eliakim and Shebna with the oldest of the priests in mourning costume to the prophet Isaiah, to entreat him to intercede with the Lord in these desperate circumstances.
(Note: “But the most wise king did not meet his blasphemies with weapons, but with prayer, and tears, and sackcloth, and entreated the prophet Isaiah to be his ambassador.” - Theodoret.)
The order of the words: Isaiah the prophet, the son of Amoz, is unusual (cf. 2Ki 14:25; 2Ki 20:1; 1Ki 16:7, etc.), and is therefore altered in Isaiah into Isaiah the son of Amoz, the prophet.