Isaiah 37:30

And this shall be a sign unto thee -It is evident that the discourse here is turned from Sennacherib to Hezekiah. Such transitions, without distinctly indicating them, are common in Isaiah. God had in the previous verses, in the form of a direct personal address, foretold the defeat of Sennacherib, and thc confusion of his plans. He here turns and gives to Hezekiah the assurance that Jerusalem would be delivered. On the meaning of the word ‘sign,’ see the note atIsaiah 7:14. Commentators have been much perplexed in the exposition of the passage before us, to know how that which was to occur one, two, or three years after the event, could be a sign of the fulfillment of the prophecy.