Rather, Rava said: Rav Idi explained the matter to me. The verse states: “Say you of the righteous who is good, that they shall eat the fruit of their actions” (Isaiah 3:10). And this verse is difficult, as is there a righteous person who is good and is there a righteous person who is not good? Rather, this verse should be understood as follows: One who is good both toward Heaven and toward people is a good righteous person; one who is good toward Heaven but bad toward people is a righteous person who is not good. Rava continues: On a similar note, it is written: “Woe to the evil wicked one, for the work of his hands shall be done to him” (Isaiah 3:11). And is there a wicked man who is evil and is there one who is not evil? Rather, one who is evil toward Heaven and evil toward people is an evil wicked person; and one who is evil toward Heaven and not evil toward people is a wicked person who is not evil. With regard to the issue at hand, only one who performs mitzvot that benefit others receives the profits of his mitzvot in this world. This does not apply to dispatching the mother bird, which is an act that does not benefit other people.
― C.S. Lewis, The Screwtape Letters