2 Kings 20:1

In those days was Hezekiah sick unto death That is, in the same year in which the king of Assyria invaded Judea; for Hezekiah reigned in all twenty-nine years, and surviving this sickness fifteen years, it must have happened in his fourteenth year, which was the year in which Sennacherib invaded him. It appears, however, from 2 Kings 20:6, in which God promises to deliver him and Jerusalem out of the hand of the king of Assyria, that it took place before that deliverance; but the sacred historian thought proper to place it after that event, that he might not interrupt the story of Sennacherib. Thus saith the Lord, Set thy house in order, &c. Make thy will, and settle the affairs of thy family and kingdom. This he the rather presses upon him, because the state of his kingdom peculiarly required it, for it is plain Hezekiah had not, as yet, any son; Manasseh, his heir and successor, not being born till three years after this time; compare 2Ki 20:6 with 2 Kings 21:1. Thou shalt die, and not live Thy disease is mortal in its kind, and will be so in effect, if God do not by a miracle prevent it. Such threatenings, though expressed absolutely, have often secret conditions.