Quenched the violence of fire - As Shadrach, Meshach, and Abednego did; Daniel 3:15-26. “Escaped the edge of the sword.” As Elijah did when he fled from Ahab, 1 Kings 19:3; as Elijah did when he was delivered from the king of Syria, 2 Kings 6:16; and as David did when he fled from Saul.
Out of weakness were made strong - Enabled to perform exploits beyond their natural strength, or raised up from a state of physical infirmity, and invigorated for conflict. Such a case as that of Samson may be referred to, Judges 15:15; Judges 16:26-30; or as that of Hezekiah, 2 Kings 20 who was restored from dangerous sickness by the immediate interposition of God; see the notes on Isaiah 38.
Waxed valiant in fight - Became valiant. Like Joshua. Barak, David, etc. The books of Joshua, Judges, Samuel, and Kings supply instances of this in abundance.
Turned to flight the armies of the aliens - The foreigners - as the invading Philistines, Ammonites, Moabites, Assyrians, etc.