How will Hashem make man like fish of the sea?
Avodah Zarah 3b #1: Just like fish die immediately if they come upon dry land, also people die immediately if they refrain from Torah and Mitzvos.
Avodah Zarah 3b #2: Just like fish die if the sun beats upon them, also people 1
Avodah Zarah 4a: Just like bigger fish swallow smaller fish, also bigger people would swallow smaller people, if not that they fear the king. If not for fear of the kingdom, people would swallow one other alive (Avos 3:2).
Rashi: He will be Hefker in front of Nebuchadnetzar like fish ? anyone who wants to trap them may trap them. Radak ? people trap hordes of them; nothing stops them. Even youths can trap them with a hook!
Ma'alos ha'Torah: Just like water covers fish, and Ayin ha'Ra does not rule over them, so it does not rule over one who engages in Torah. 2
Malbim: Do not say that this was without Your Hashgachah and knowledge; You abandoned men to chance, and hid Your face. This cannot be ? would You make man like fish, that a big fish swallows a small fish?!
3b: Some say that this refers to this world; all sicknesses are decreed by Heaven, except for chills and fevers (they are due to negligence). Some say that it refers to the world to come. Gehinom is not a separate place. Rather, Hashem will let the sun beat down heavily. The wicked are judged (punished) through this, and Tzadikim are cured through this. Ma'alos ha'Torah ? even if the sun does not beat on it, a fish taken out of water will die! There are fish that can live several hours on the dry land ? but if the sun beats on them, they die immediately. So if a Chacham separates from Torah only for his need for income, and returns to learn right after, this is proper. If he sinks in follies of this world, and its desires burn in His heart, he dies immediately, and anyone who separates from Divrei Torah, he falls in Gehinom' (Bava Basra 79a).
He cites this from the Gemara. It is not in our Gemaros. (PF)
How will Hashem make man "k'Remes Lo Moshel Bo"?
Radak: These are small Sheratzim. Man seizes them as he desires, for no one rules over him to stop him. So You made people Hefker in front of this Rasha!
Malbim: Surely You would not make man like vermin, over which no one rules. The sea protects fish; a hook or strategies are needed [to catch them]. One can take Remes with his hand on the land ? they are trapped easily?!