What does the Bible tell us about the illness that struck Hezekiah?
Hezekiah became ill to the point of death (2 Kings 20:1). Although the nature of the illness is not specifically stated, it involved a boil that was treated by a poultice (2 Kings 20:7).

Isaiah the prophet instructed Hezekiah to set his house in order because he was going to die (2 Kings 20:1). The news caused Hezekiah to weep and to cry out to the Lord in prayer (2 Kings 20:2-3).

Once again, God heard the sincere prayer of Hezekiah and told Isaiah to inform the king that God would add fifteen years to his life and deliver and defend Jerusalem from the Assyrians (2 Kings 20:5-6).

As a confirmation that these things would happen, God caused the sun to move backwards ten steps (perhaps degrees) on the stairway of Ahaz, believed to have been a sundial or time-telling device (2 Kings 20:8-11).

Who came to visit Hezekiah after his recovery?
The Babylonians sent envoys with letters and a gift to Hezekiah after his recovery (2 Kings 20:12). These envoys were also interested in hearing about the turning back of the shadow on the sundial (see 2 Chronicles 32:31). From a practical standpoint, they were probably also interested in the prospect of an alliance to keep the Assyrians in check. Hezekiah was so pleased by their overtures that he showed them everything in his house, armory, and treasury (2 Kings 20:13-15).

Isaiah was not pleased to learn of Hezekiah’s actions and prophesied that Babylon would carry away Judah’s treasures and members of the royal family (2 Kings 20:16-19). The writer of Kings noted that the rest of Hezekiah’s acts, including the tremendous engineering feat of the tunnel, are detailed in the book of Chronicles (see 2 Chronicles 29-32). After Hezekiah died, “Manasseh his son became king in his place” (2 Kings 20:21).