Rashi citing Targum Yonasan: A king with his camp will come upon them like a lion that ascends from the height of the Yarden to a shepherd's pen. Radak (49:19) - it will be as easy for him to conquer as a shepherd's pen. The Targum of Neve is a pen, like "Nevos Keros Ro'im" (Tzefanyah 2:6). Eisan - the place that is strong now, will be [weak] like a shepherd's pen.

Radak: The one who will destroy Bavel will ascend like a lion, without fear. He will ascend from Ge'on ha'Yarden, i.e. he will increase and overpower like water increases when the Yarden overflows its banks. "Neve Eisan" is a strong place, i.e. Bavel.

The [primary] city of Malchus Bavel is metaphorically called a habitation of flocks. A tearing lion comes upon it from Ge'on ha'Yarden; the very strong lions are there. I.e. a strong king will come to conquer it. (Based on Malbim 49:19 - PF.)

Rashi: It is a place of lions.

Radak: It is in Eretz Yisrael. The evil will come to Bavel from Ge'on Yisrael, i.e. as punishment for [what they did to] Yisrael, and Yisrael will rise to supremacy via the king who conquers Bavel.

Rashi: When I will bring the time.

Radak #1: When I will make Yisrael quiet and calm...

Refer to 49:19:3:3-4.

Rashi: I will quickly remove [the enemy] from on top of [Bavel].

Radak: I will remove Yisrael from Eretz Bavel, where they were exiled.

Malbim: I will make the lion leave this habitation of flocks for a moment. He will go back to his place [but return very soon].

The one whom I chose to take My vengeance, I will appoint him on [Bavel. This is based on Rashi (49:19) - PF.]

Radak: Whoever is a warrior, I will appoint him on Eretz Bavel.

Malbim: The enemy will return (refer to 50:20:4:4) to this habitation of flocks. I will appoint over this place all chosen warriors. All will gather against it for war.

Refer to 49:19:6:1-2.

Refer to 49:19:7:1-3.

Who is Melech Bavel, that he will stand in front of Me?! (This is based on Radak (49:19) - PF.)

Refer to 49:19:8:2-3.

Refer to 49:19:9:1-2.