At that time: i.e. shortly after the two miracles of the shadow and Hezekiah's recovery from his sickness. Compare 2Ch_32:31.
letters and a present. These were more potent than Sennacherib's hosts; just as Ahab's daughter and feast were than his men of war with Jehoshaphat. See 2Ch_18:1-3. Compare with 2Ch_17:1-3.