Behold, I will send a blast upon him, and he shall hear a rumour, and return to his own land; and I will cause him to fall by the sword in his own land.
Blast - or else, 'I will put a spirit (Isaiah 28:6; 1 Kings 22:23) into him; i:e., so influence his judgment that when he hears the report (Isaiah 37:9, concerning Tirhakah), he shall return (Gesenius); the "rumour" also of the destruction of his army at Jerusalem, reaching Sennacherib, while he was in the southwest of Palestine on the borders of Egypt, led him to retreat. The English version seems to me more spirited and more in accordance with the parallelism: "a blast" answering to "a rumour" in the parallel clause. The rumour was like a deadly blast from the Lord, blighting his hopes. Compare as to the anti type, the willful king, Daniel 11:44, "tidings out of the east and out of the north shall trouble him."
By the sword - (Isaiah 37:38: cf. Nahum 1:9-13.)