Isaiah 31

5. As in the image of "the lion," the point of comparison is the fearless might of Jehovah; so in that of the birds, it is His solicitous affection ( Deuteronomy 32:11 , Psalms 91:4 , Matthew 23:37 ).
flying--Rather, "which defend" their young with their wings; "to fly" is a secondary meaning of the Hebrew word [MAURER]. "Hovering over" to protect their young [G. V. SMITH].
passing over--as the destroying angel passing over, so as to spare the blood-marked houses of the Israelites on the first passover ( Exodus 12:13 Exodus 12:23 Exodus 12:27 ). He passed, or leaped forward [LOWTH], to destroy the enemy and to spare His people.

6. The power and love of Jehovah, just mentioned, are the strongest incentives for returning to Him ( Ezekiel 16:62 Ezekiel 16:63 , Hosea 6:1 ).
ye . . . Israel--The change of person marks that when they return to the Lord, He will address them in more direct terms of communion in the second person; so long as they were revolters, God speaks of them, as more at a distance, in the third person, rather than to them.

7. In the day of trial the idols will be found to render no help and will therefore be cast away. Compare as to the future restoration and conversion of Israel simultaneously with the interposition of Jehovah in its defense, Zechariah 12:9-14 , Zechariah 13:1 Zechariah 13:2 .
for a sin--that is, whereby especially you contracted guilt ( 1 Kings 12:30 ).

8. Assyrian--Sennacherib, representative of some powerful head of the ungodly in the latter ages [HORSLEY].
sword, not of . . . mighty . . . mean man--but by the unseen sword of God.
flee--Sennacherib alone fled homewards after his army had been destroyed ( Isaiah 37:37 ).
young men--the flower of his army.
discomfited--rather, "shall be subject to slavery"; literally, "shall be liable to tribute," that is, personal service ( Deuteronomy 20:11 , Joshua 9:21 ) [MAURER]. Or, not so well, "shall melt away" [ROSENMULLER].

9. Rather, "shall pass beyond his strongholds"; he Shall not stop to take refuge in it through fear ( Judges 20:47 , Jeremiah 48:28 ) [GESENIUS].
ensign--the banner of Jehovah protecting the Jews [MAURER].
fire . . . furnace--"light" and "fire," namely, of Jehovah's altar at Jerusalem ( Isaiah 29:1 ). Perhaps "furnace," as distinguished from "fire," may mean that His dwelling-place (His hearth) was at Jerusalem (compare Isaiah 4:5 ); or else the fiery furnace awaiting all the enemies who should attack Jerusalem.