The sudden and fierce downfall of Babylon unfolds through the vivid image of a lion bursting from its lair to devour a peaceful flock. This specific prophetic style mirrors the judgment pronounced against Edom, as both of these nations shared the heavy guilt of destroying God's Temple [מלבי״ם]. In this unfolding judgment, God acts as the absolute ruler of the world, leaving the Babylonians with no possible way to escape Him [ביאור שטיינזלץ].
The attacking enemy, identified as the king of Persia, will strike with massive force and without fear, much like a leaping lion. This lion emerges from a place of dense vegetation and high valleys near the Jordan River, which served as a natural habitat for lions [רש״י, מצודת ציון, ביאור שטיינזלץ]. However, this origin point carries deeper meanings. It can represent the overwhelming surge of river waters overflowing their banks, or it can serve as a reminder that this disaster strikes Babylon as a direct punishment for harming Israel, meaning the retribution ultimately stems from Israel itself [רד״ק].
The lion pounces upon a highly secure and fortified dwelling [מצודת ציון, רד״ק]. Alternatively, this target is pictured as a rich, excellent pasture where a shepherd sits comfortably with his fattened flock [מצודת דוד, ביאור שטיינזלץ].
When detailing how quickly this event unfolds, there are two primary ways to understand God's action. The first approach focuses on speed and timing. When the right moment arrives [רש״י], God will send the attackers in the blink of an eye to storm the empire [מלבי״ם, ביאור שטיינזלץ]. The second approach focuses on the concept of rest and relief. Because God desires to grant peace and quiet to the people of Israel, He will swiftly rush them out of their Babylonian exile so they can finally return to their own land [מצודת דוד, רד״ק]. To accomplish this swift victory, God will appoint and command elite, chosen fighters to wage war against Babylon [רד״ק, מצודת ציון, ביאור שטיינזלץ].
The prophecy concludes with a powerful declaration of God's absolute might. There is no one who can protest against His actions [מצודת דוד], nor is there anyone who can challenge Him by setting a designated time for battle [רש״י, מצודת דוד, מצודת ציון]. Ultimately, no human leader or shepherd could ever stand before God and save his people from His hands [מצודת דוד].