Turn with me to Isaiah 38, in which we read of King Hezekiah's illness and recovery. In Isaiah 39, we have an account of envoys coming from Babylon to congratulate King Hezekiah on his recovery. There is a parallel account of those events in 2 Kings 20 which appear to be textually dependent on Isaiah (or vice versa). Here is the account in Isaiah 39:1-2:
At that time Merodach-baladan the son of Baladan, king of Babylon, sent envoys with letters and a present to Hezekiah, for he heard that he had been sick and had recovered. And Hezekiah welcomed them gladly. And he showed them his treasure house, the silver, the gold, the spices, the precious oil, his whole armory, all that was found in his storehouses. There was nothing in his house or in all his realm that Hezekiah did not show them.Thus, we learn, King Hezekiah proudly showed the Babylonian envoys his great riches in his treasure house. Hezekiah's pride brings upon him a prophecy of judgment. In verses 3-7, we read,
Then Isaiah the prophet came to King Hezekiah, and said to him, “What did these men say? And from where did they come to you?” Hezekiah said, “They have come to me from a far country, from Babylon.” He said, “What have they seen in your house?” Hezekiah answered, “They have seen all that is in my house. There is nothing in my storehouses that I did not show them.” Then Isaiah said to Hezekiah, “Hear the word of the Lord of hosts: Behold, the days are coming, when all that is in your house, and that which your fathers have stored up till this day, shall be carried to Babylon. Nothing shall be left, says the Lord. And some of your own sons, who will come from you, whom you will father, shall be taken away, and they shall be eunuchs in the palace of the king of Babylon.”King Hezekiah selfishly is relieved at the prophecy, thinking to himself that at least "There will be peace and security in my days" (verse 8).
Both the account of this event that we read in Isaiah and that in 2 Kings imply that Hezekiah's fell ill at the time of the invasion by Sennacherib of Judah and before the outcome of that invasion. In both accounts, God promises Hezekiah that he will live and that God will deliver the city from the Assyrians (Isaiah 38:6; 2 Kings 20:6). Thus, the envoys arrived from Babylon after his recovery, and after the danger from Assyria had been averted.
Now let's consider another text in 2 Kings 18:13-16:
In the fourteenth year of King Hezekiah, Sennacherib king of Assyria came up against all the fortified cities of Judah and took them. And Hezekiah king of Judah sent to the king of Assyria at Lachish, saying, “I have done wrong; withdraw from me. Whatever you impose on me I will bear.” And the king of Assyria required of Hezekiah king of Judah three hundred talents of silver and thirty talents of gold. And Hezekiah gave him all the silver that was found in the house of the Lord and in the treasuries of the king's house. At that time Hezekiah stripped the gold from the doors of the temple of the Lord and from the doorposts that Hezekiah king of Judah had overlaid and gave it to the king of Assyria.Wait a minute. So Hezekiah has just made this humiliating tribute to the king of Assyria, having had to offer him "all of the silver that was found in the house of the Lord and in the treasures of the king's house" and even being reduced to stripping the gold from the doors of the temple and from the doorposts. How then was he able not long after this humiliation to show all of his riches of his treasury to the Babylonian envoys? One could write it off as a contradiction, or we could dig deeper to find the solution - and in so-doing uncover another remarkable undesigned coincidence.
For the solution, let us now turn to 2 Chronicles. 2 Chronicles contains the account of the destruction of Sennacherib's army by the miraculous intervention of the angel of the Lord (which is also found in Isaiah and 2 Kings albeit in different wording and terminology from the account in 2 Chronicles). After these events, 2 Chronicles throws in a unique detail in 32:23:
And many brought gifts to the Lord to Jerusalem and precious things to Hezekiah king of Judah, so that he was exalted in the sight of all nations from that time onward.Therein lies our answer. This explains how Hezekiah came to have a full treasury to show off to the Babylonian envoys by the time the Babylonians learned of his recovery. No mention is made of the humiliating tribute to the Assyrians in 2 Chronicles. 2 Kings does mention the humiliating tribute and him showing off his treasury shortly thereafter to the Babylonian envoys, but makes no mention of the gifts that replenished the treasury. Isaiah makes no mention of the tribute or the gifts but mentions his display of his great wealth.
This undesigned coincidence corroborates the historical veracity of these events and also strongly suggests that one of our authors (i.e. either Isaiah or the author of 2 Kings) had access to the court of Hezekiah, and thus knew about the visit of the Babylonian envoys.