Isaiah 39:7
And of thy sons that shall issue from thee, which thou shalt beget, shall they take away; and they shall be eunuchs in the palace of the king of Babylon. And of thy sons that shall issue from thee, which thou shalt beget, shall they take away; and they shall be eunuchs in the palace of the king of Babylon.
The verse foretells that Hezekiah's descendants issuing from him would be taken away from Judah to Babylon and made eunuchs in the palace of the king of Babylon. This personal judgment belonged to a wider coming captivity in which all the treasures in his house, the wealth laid up by his fathers, and the stored goods of Jerusalem would be carried away to Babylon. The prophecy stands in the history of Hezekiah after God raised him up from sickness and added fifteen years to his life.
The judgment came because Hezekiah showed Babylonian ambassadors and visitors the treasures and riches of his kingdom and house, of Jerusalem, and of God's house, including sacred things and his advantages. Their report and sight of those treasures would lead the king of Babylon and his counselors to plan to take those riches for themselves and to enrich Babylon with what had been seen. In this way his display foreshadowed the loss of his possessions and the deportation of his descendants to serve in the Babylonian king's palace.
The episode stands as a comparison and warning against displaying the Lord's riches and resources to strangers and to others, since such display can expose pride and self-exaltation and bring a person under God's test and judgment. It warns that betraying a sacred trust and leaning upon unbelievers instead of God brings ruin and weakens the example set for others. The exposure of Hezekiah's treasures likewise warns that for an institution to reveal its private affairs and resources to outsiders is an unwise mistake that can cause harm.
That institutional exposure remains unwise even when doing so brings a promised contribution. The heavy judgment that followed Hezekiah's showing of sacred things from God's house to enemies warns against making the church's private troubles and weaknesses known to the wicked. Church affairs are to be kept within the church, with the exception that a personal injury must be confessed to the person harmed.