Will he not have any good at all?
Ibn Ezra: He will not have any good in his end. Ibn Ezra (7:3) - this is the norm (there are exceptions).
Seforno: He will not have any significant good. His reward [for his good deeds] will be inferior.
Metzudas David: He will not have good in the world to come. His Nefesh will be cut off quickly, and he will not be there many days. He will be like a shadow, which does not last in one place. It moves quickly from its place via the sun's movement.
What do we learn from "[v'Tov Lo Yihyeh la'Rasha] v'Lo Ya'arich Yamim k'Tzel [Asher Einenu Yarei mi'Lifnei Elokim]"?
Rav Sadya Gaon: One who does not fear Elokim, he will not have any good, and his days will not extend 1 . He is like a shadow that ends quickly.
Ibn Ezra: Some Resha'im, their days will not extend, like a shadow.
Rashbam: He passes from the world like a fleeting shadow.
Seforno: Also his inferior reward will be for a short time, like that of a shadow.
Rav Sadya Gaon (12) explained that the sinner can do evil for 100 years! Perhaps he means that since he will not live eternally, he is like a fleeting shadow. Alternatively, our verse is the norm; there are exceptions, like Ibn Ezra said (7:3). (PF)
Why does it say "[v'Tov Lo Yihyeh la'Rasha v'Lo Ya'arich Yamim k'Tzel] Asher Einenu Yarei mi'Lifnei Elokim "?
Kidushin 33b: This refers to one who does not rise for a Chacham, about which it says "v'Yareisa me'Elokecha". Do not say that it refers to Ribis or false measures, about which it says "v'Yareisa me'Elokecha." A Gezeirah Shavah "Pnei-Pnei" teaches that it applies here.
Rashi: He will not have good because he does not fear Elokim.
Ibn Ezra: There are different kinds of Resha'im. Here it discusses one who does not fear Elokim.
Seforno: This is why his reward will be inferior. Even if it is for a good deed, it is considered inferior. Since he does not fear Elokim, it was Lo Lishmah.
