What is "Megoras Rasha"?
Rashi: It is what he fears 1 ; it will come. Dor ha'Flagah feared "Pen Nafutz", and in the end "va'Yafetz Hashem Osam mi'Sham" (Bereishis 11:4, 8).
Malbim: It is what he fears and hides from it, and makes strategies to be saved from it. (This distinguishes Megorah from other expressions of fear.) Even so, it will come.
R. Yonah: He will not get his desire, only what he fears.
Who gives the desire of Tzadikim?
Rashi: The One who has ability to give it. R. Yonah - they desire His Chesed and hope to Him. Their fear from the enemy and "Akas Rasha" (Tehilim 55:4) will not come.
Malbim: Not only will evil not befall Tzadikim - via Hashgachah, Hashem gives even what they desire in the heart, without doing anything to get it!