5 Then Isaiah said to Hezekiah, “Hear the word of the LORD Almighty: 6 The time will surely come when everything in your palace, and all that your fathers have stored up until this day, will be carried off to Babylon. Nothing will be left, says the LORD. 7 And some of your descendants, your own flesh and blood who will be born to you, will be taken away, and they will become eunuchs in the palace of the king of Babylon.”
Isaiah is reprimanding Hezekiah in this passage. Hezekiah, in a display of wealth, tried to impress the Babylonians but all it lead to was for Babylon to mark Judah as their next target. Incidentally, 100 years later, Judah was sacked by the Babylonians. Isaiah warns Hezekiah of the coming judgement. Hezekiah responds.
8 “The word of the LORD you have spoken is good,” Hezekiah replied. For he thought, “There will be peace and security in my lifetime.”
The sad part is, Hezekiah does not worry since there is peace in his lifetime. He is not worried about what happens there after and is glad that he will experience peace and security.