Who is a Kesil?
Rashi: He is a Rasha.
Ibn Ezra: They are lazy fools; they do not have envy.
Rid: Also one who does not want to work at all, even for his needed income, is a Kesil. It is proper to work for one's needs!
Why does the Sefer teach about a Kesil here?
Ri Kara, Seforno: After teaching that all toil and Kishron ha'Ma'aseh is Hevel, for in the end his toil will pass to others, one might have thought that he should be idle. Our verse refutes this.
What does the Kesil do?
Rav Sadya Gaon: [He is idle] due to lack of ability.
Rashi: He does not want to toil to eat. Rather, he steals.
Ibn Ezra, Rashbam: He does not engage in work to eat from it. Rather, he sits idle and eats what he has, and he is left without food.
Metzudas David: He clenches his arms together 1 - i.e. he does not move them to work to keep himself alive.
Metzudas Tziyon: Chovek is surrounding something with his hand.
Does he eat his flesh?!
Rashi, citing Sifri Re'eh 53: On the days of judgment, he will see Tzadikim honored, and he is judged.
Ibn Ezra: After he eats what he has and he is left without food, it is as if he eats his flesh, for he will starve to death.
Rashbam: He has nothing to eat other than his own flesh. He degenerates and decays. Rather, one should engage in work, so he will be financed honorably.
Ri Kara: He consumes the property that he had to finance his household, who are his flesh.
Seforno: Due to the pain of poverty and lack of essentials for temporary life [it is as if he eats his flesh].
Metzudas David: This is a metaphor. He will have nothing to eat, and the fatness of his flesh will become thin due to hunger. It is as if he ate his flesh due to lack of food.
