Rashi: They are like iron hooks. Radak ? because he is compared to a Tanim, the verse discusses catching him via a hook. It punctures the jaws, and they raise it out of the water ? "uv'Cho'ach Tikov Lecheyo" (Iyov 40:26).

Malbim: A fish-hook is a Mashal for Egypt, which was destroyed several times. Initially, Pharaoh ruled until the Pras river. Nebuchadnetzar struck him when Yehoyachin became king (Melachim II, Perek 24), and also in Yehoyakim's fourth year Karkamish struck him (Yirmeyah Perek 46). He went out a third time when he came against Yerushalayim, and returned to his land (Yirmeyah 37). All this was out of his land. This is compared to putting a hook in his jaws, just like they pull a big fish against its will. Then he was forced to leave Egypt via Hashem's decree, to punish him.

Rashi: I will put in the heart of all your Giborim to go out with you to war, and all of them will fall. Radak ? Degas is a Klal for all fish. When it is not Samuch, it is Dagah ? "veha'Dagah Asher ba'Y'or Tamus" (Shemos 7:18). When they pull you out of the river, they will come up with you. This is a Mashal for the Egyptians ? officers, cavalry, Giborim and the lowest people, all will perish.

Malbim: This is a Mashal ? all fish of the river will stick to the scales [of the big Tanim], i.e. his officers and Giborim. They will be taken out of his rivers, i.e. they will leave his land. He was secure in his land ? but out of his land, he was like a fish taken out of the water to the dry land; it is weak.