Wajazao sayyi-atin sayyi-atun mithluha faman AAafa waaslaha faajruhu AAala Allahi innahu la (surah shura: 40)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(42:40) The recompense *64 of evil is evil the like of it. *65 But he who forgives and makes amends, his reward lies with Allah. *66Surely He does not love the wrong-doers. *67

Wa jazaaa`u saiyi`atin saiyi`tum misluha faman `afaa wa aslaha fa ajruhoo `alal laah; innahoo laa yuhibbuz zaalimeen

*64) The passage from here to the end of verse 43 is an explanation of verse 39.
*65) This is the first fundamental principle which must be borne in mind in retaliation. The right limit of retaliation is that one should return the same sort of ill treatment that one has received; one has no right to return a greater ill treatment.
*66) This is the second principle. It means: Although it is permissible to retaliate against the one who has committed a violence, wherever pardoning can be conducive to reconcilement, pardoning is better for the sake of reconcilement than retaliation. And since man pardons the other by suppressing his own feelings, Allah says that the reward of such a one is with Him, for he has suppressed his own self for the sake of reforming the evil-doers.
*67) In this warning allusion has been made to a third principle about retaliation, and it is this: One should not become a wrongdoer oneself in the process of avenging a wrong done by the other. It is not permissible to do a greater wrong in retaliation for the wrong done. For example, if a person gives another a slap, the other can return only one slap; he cannot shower blows and kicks. Likewise, it is not right to commit a sin in retaliation for a sin. For example, if a wicked man has killed the son of someone, it is not right to go and kill the son of the former. Or, if a mean person has violated the chastity of a person's sister or daughter, it is not lawful for him to commit rape on the former's sister or daughter.