Who are" ha'Omerim la'Ra Tov [vela'Tov Ra]"?
Sotah 41b: They are flatterers. Refer to 5:24:3:2.
Rashi: They praise idolatry, and it is bad in their eyes to serve Hashem, who is good.
Radak: They say that their evil deeds are good, and engaging in Torah and Chachmah are bad and [pointless] toil.
Malbim: Man discerns in three ways. (a) Via intellect, e.g. between true good and true evil, e.g. Mitzvah and sin. (b) The power of comparison, nto distinguish what helps from what does not help, e.g. light and darkness. (c) Senses distinguish between pleasant and unpleasant, e.g. honey and wormwood. Ill people [sometimes] taste bitter to be sweet and vice-versa, and people with eye maladies imagine light to be dark and vice-versa. So people with maladies of the Nefesh consider good to be evil and vice-versa.
Kesav Sofer (Devarim 32:19): They say that Yir'ei Hashem and Tzadik are evil and go in darkness, and the sinners are Tov, and they have the light of Chachmah and understanding.
How do they consider darkness to be light?
Rashi: Something that will bring darkness on them, they say that it will illuminate for them.
Radak: Since their intellect does not distinguish between good and evil, they are like one whose senses of sight and taste do not distinguish, and lie to them.
Malbim: Confusing good and evil due to a malady of the Nefesh is like confusing darkness with light, or bitter with sweet. (Refer to 5:20:13:3.)
How do they consider bitter to be sweet?
Rashi: Sin, for which Hashem will bring bitter punishments on them, they say that it will be sweet.
Radak: Refer to 5:20:2:2.
How do they consider sweet to be bitter?
Rashi: Avodas Hashem, which is sweet, they say that it is bitter.
