The position of the oppressed in relation to the oppressor:
Allah Says (what means): “And those who, when tyranny strikes them, they defend themselves. And the retribution for an evil act is an evil one like it, but whoever pardons and makes reconciliation - his reward is [due] from Allah. Indeed, He does not like wrongdoers. And whoever avenges himself after having been wronged - those have not upon them any cause [for blame]. The cause is only against the ones who wrong the people and tyrannise upon the earth without right. Those will have a painful punishment. And whoever is patient and forgives - indeed, that is of the matters [requiring] determination [i.e. on the part of those seeking the reward of Allah].” [Quran 42: 39-43]
Theses verses include two matters:
First: Taking revenging from the oppressor.
Second: Forgiveness on the part of the oppressed.
Ibraheem said: “The believers hated anyone to humiliate them, but whenever they had the chance to take revenge, they would forgive instead.”
Allah praises the believers in the abovementioned verses for having the strength and power to avenge in a just manner, for restoring their rights, and for not allowing aggressors to take advantage of them. They are by no means incapable, weak or humiliated, and they are quite capable of exacting revenge, yet they forgive and forget.
This is how Prophet Yoosuf acted with his brothers despite his ability to take revenge from them. Likewise, the Prophet forgave the man who attempted to kill him whilst he slept; the man was suddenly overcome with fear of the Prophet and therefore dropped the sword from his hand, and the Prophet took hold of it and forgave him, even though he could easily have killed him.
There are many Quranic verses and prophetic narrations addressing this issue and encouraging the oppressed to forgive the oppressor when he is in a position to exact revenge, as this will boost his record of rewards on the Day of Resurrection. On the other hand, if the oppressed insists on revenge then this is his right and it is perfectly permissible to do so, but the revenge must be strictly limited to the extent that he was wronged. If the wronged person is one of two wives, it is permissible for the husband to enable the wronged one to gain revenge, as the Prophet permitted, one of his wives to get back at another one who had badmouthed her.
The supplication of the oppressed against the oppressor:
It is permissible for the oppressed to supplicate against the one who transgressed his rights, and this is a form of revenge. The wronged person has the choice to avenge, to supplicate against the one who wronged him, to persevere and wait until Allah returns his right for him in the Hereafter, or to forgive. The best of all of these is to forgive and to do so would attain the greatest reward from Allah in the Hereafter.
The permissibility of the oppressed taking what was taken from him by his oppressor if he finds it:
It is permissible for the oppressed to do this, and it is also permissible for him to take something of the same value of the oppressor’s property, but he may not go beyond that. Similarly, if someone was badmouthed, then he may badmouth the one who badmouthed him but may not say more than what was said to him, or else he is a sinner, as the Prophet said: “Whatever two people say (from ill words) then both their sins lie with one who initiated, as long as the wronged does not transgress (i.e. exceed the extent to which he was wronged).” This means that whatever they say to one another will all go into the record of the one who initiated, as he was the cause of all of it, but if the wronged person retaliates with more than what he was wronged with, then this is a sin on his part which the other person will not bear.
Along the same lines, one should not supplicate against the one who wronged him with that which would neither yield benefit to him nor help him retrieve his rights that were taken; it is better for him to simply supplicate to Allah for his rights being returned. The only exception to this is when the person being supplicated against is a disbeliever, in which case he may do so.
Forgivingness versus revenge:
The last two verses [42-43] of Chapter Ash-Shooraa' which were mentioned above and which mean: “The cause is only against the ones who wrong the people and tyrannies upon the earth without right. Those will have a painful punishment. And whoever is patient and forgives - indeed, that is of the matters [requiring] determination [on the part of those seeking the reward of Allah]” [Quran 26: 42-43] These verses confirm that the blame lies with the one who initiated the oppression and transgression, while the one who perseveres through it, is doing something praiseworthy, and will be highly rewarded.
Al-Fudhayl Ibn ‘Iyadh said: “If a man comes to you complaining about another man who wronged him, then advise him to forgive him. If he says, `I cannot bring myself to forgive him and would rather utilise the right granted to me by my Lord to avenge` then say to him: `If you can limit yourself to avenging in a fair manner, without transgressing the limits to which you were wronged, then proceed; but if you cannot control yourself, then it is safer to return to the option of forgiving him as the reward for the one who forgives is great with Allah.”
The one who forgives can sleep at night in a relaxed manner with no fear that he may have exceeded the extent to which he was wronged, because he did not avenge at all. However, the one who sought vengeance will agonise and think to himself: "Did I transgress? Did I go beyond my limit?"
Forgiving is a high rank which the callers to Islam should possess as it is a rank that only those with a high status attain, and they are the ones whom people take as examples to follow.
Abu Hurayrah narrated that a man once badmouthed Abu Bakr while the Prophet was sitting with them, and the Prophet expressed wonder and smiled. The man continued, and after he had said much more, Abu Bakr retorted with some of the same, which caused the Prophet to get up (to leave) with an angry expression on his face. Abu Bakr said: ‘O Messenger of Allah! He badmouthed me while you were sitting there! Why did you become upset and leave when I answered back to some of what he had said?’ The Prophet said: “You had an angel retorting on your behalf (when you were silent), but when you began answering him back (i.e., the man), Satan arrived, and I was not going to sit in the presence of Satan.” Then he said: “O Abu Bakr! Here are three matters, all of which are true: Whenever a man is oppressed but forgives for the sake of Allah the Most High and the Almighty, then Allah will honour him with victory…” [Ahmad]