What do we learn from "Zeh Darkam Kesel Lamo"?
Rashi (from Shabbos 31b): Resha'im know that they go on the path of death, yet they have Chelev covering their kidneys, so their kidneys do not counsel them to change their ways.
Rashi: Their path is folly.
Radak: This is their path, for they are foolish, and do not know to do straightly.
Malbim: How can they go on such a foolish path, to hope for wealth that will publicize after their death that they were like animals?!
Why does it say "v'Achareihem b'Fihem Yirtzu"?
Rashi (from Shabbos 31b): Do not say that Resha'im forgot that they will die in the end. They talk about their end, and they are not afraid!
Rashi: Those who come after them will speak about what happened to them (the earlier ones). "Yirtzu" is telling matters.
Radak #1: Their children after them will desire what they heard their parents praising - wealth, and will cling to their path with all their strength.
Radak #2: Their children will be like them and share their mindsets. This is like "Ish l'Fi Achlo" (Shemos 12:4), "Ish k'Fi Avodaso" (Bamidbar 7:5).
Malbim: How will their mouths reveal their desire at the time of their death, when they will say who will inherit them? Is there greater folly than this?!
