Then said Hezekiah to Isaiah, Good is the word of the LORD which thou hast spoken. He said moreover, For there shall be peace and truth in my days. Then said Hezekiah - The nature of Hezekiah's crime, and his humiliation on the message of God to him by the prophet, is more expressly declared by the author of the book of the Chronicles: "But Hezekiah rendered not again according to the benefit done unto him; for his heart was lifted up; therefore there was wrath upon him, and upon Judah and Jerusalem. Notwithstanding, Hezekiah humbled himself for the pride of his heart, both he and the inhabitants of Jerusalem, so that the wrath of the Lord came not upon them in the days of Hezekiah. And Hezekiah prospered in all his works. Howbeit, in the business of the ambassadors of the princes of Babylon, who sent unto him to inquire of the wonder that was done in the land, God left him, to try him, that he might know all that was in his heart." 2 Chronicles 32:25, 2 Chronicles 32:26, 2 Chronicles 32:30, 2 Chronicles 32:31.
There shall be peace and truth in my days - I rather think these words should be understood as an humble inquiry of the king, addressed to the prophet. "Shall there be prosperity, שלום shalom, and truth in My days? - Shall I escape the evil which thou predictest?" Understood otherwise, they manifest a pitiful unconcern both for his own family and for the nation. "So I be well, I care not how it may go with others." This is the view I have taken of the passage in 2 Kings 21:19. Let the reader judge whether this, or the former, should be preferred. See the concluding notes on 2 Kings 20.
Commentary on the Bible, by Adam Clarke [1831].