Isaiah 39:8
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 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.
This verse belongs to the time after Hezekiah's recovery, when God left him to be tested by the visit of Babylon's ambassadors in order to reveal what was in his heart. In that testing he showed the Babylonian visitors the treasures and resources of the house of God and of his kingdom. That disclosure was a mistake, indeed a heinous sin in exposing what was sacred to the enemy.
His display was driven by pride and reliance on his own achievements instead of giving God the honor. He used the Lord's resources for human honor rather than for God's work, in hope of gaining influence. The plan to gain influence backfired, for the visitors left planning to take those advantages for themselves. The display tempted Babylon to plunder what had been shown and began his downfall.
Isaiah then foretold God's heavy judgment that Judah's treasures would be carried away to Babylon and some of Hezekiah's descendants taken there. Hezekiah accepted that word from the Lord as good, understanding that there would be peace and truth and the threatened judgment would not fall during his own lifetime. He later humbled himself for his pride.
The episode warns that betraying a sacred trust through alliance with unbelievers and reliance on them instead of God brings loss of God's favor, weakens one's example to others, and brings consequences according to one's deeds. It warns against trusting outsiders or seeking influence through dealings with them while failing to discern their intentions. It warns against exposing an institution's private books and affairs to outsiders, since the resulting harm can be far greater than any financial benefit they may offer.