Ruling on forgiving future offenses
27-7-2014 | IslamWeb
Question:
Is it allowed for someone to make a predisposed decision that they will forgive whoever on this earth backbites or harms them in some way, whether the person is aware of it or not. Basically even if someone backbites you but you were never aware of it, can you make a decision beforehand to seek forgiveness for all those who do that, so that Allah may forgive you? Or can you only forgive sins that have already occurred? ASalama alaikum.
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad 
is His slave and messenger.
It is permissible for a Muslim to renounce some of his rights related to the past; some scholars are of view that it is desirable to do so. This is indicated by the general meaning of the Hadeeth where the Prophet said: “Keep ties with those who sever ties with you, give (in charity to) those who do not give you, and forgive those who wronged you.” [Ahmad] [Al-Haythami accredited its narrators in Majma’ Az-Zawaa'id, and Al-Albaani classified it as Saheeh (sound)]
They also supported their view by a Mursal Hadeeth (i.e. a Hadeeth narrated by a Tabi'i [successor of the Prophet's Companions]) narrated by Abdur-Rahmaan ibn ‘Ajlaan that the Prophet said: “Is not one of you able to be like Abu Dham-Dham? They (the Companions) asked: “Who is Abu Dham-Dham?” He said: “He was a man from the people before you and he used to say when he gets up in the morning: “I forgive everyone who insulted me.” [Abu Daawood]
This Hadeeth was reported by Ibn As-Sunni, Al-Bazzaar and Al-‘Uqayli on the authority of Anas 
with a weak chain of narrators as stated by Al-'Iraaqi.
However, it is understood that the Hadeeth refers to previous insults, as stated by Ibn Muflih in Al-Furoo’.
Besides, Abu Daawood entitled a chapter on this topic saying: "Chapter on a man who forgives another man who backbit him."
As regards a right that is related to the future, some scholars are of the view that it is not allowed to renounce it, arguing that this may lead to making backbiting and insulting permissible, as well as other matters related to one’s honor.
It was also reported that Ibn Seereen said: “It is not me who has forbidden backbiting so that I might have the right to make it lawful. It is Allaah who has forbidden backbiting, and I would never ever make lawful what Allaah has forbidden.” An-Nawawi said in his book Al-Athkaar while commenting on this account: .... or that the words of Ibn Seereen could be interpreted to mean that he will never make permissible for anyone to backbite him, and this is correct; for if a man says: “I forgive whoever has transgressed against my honor, this does not make backbiting him permissible; rather, it is forbidden for anyone to backbite anybody else… . As regards the Hadeeth which reads: “Is not one of you able to be like Abu Dham-Dham who used to say when he goes out of his house ‘I forgive anyone who has backbit me’ ”, what this means is: "I do not ask justice from whoever has wronged me, neither in this worldly life nor in the Hereafter." This is valid for whoever wants to renounce any injustice that occurred before it was forgiven. As for what happens after it, then there must be a new forgiveness.” [End of quote]
Moreover, Shaykh 'Abdul Muhsin Al-‘Abbaad said in his commentary on Sunan Abu Daawood: “It is not correct for a man to say: 'Talk (as you wish) about me [i.e. he allows anybody to backbite him].' However, if he forgives anything that has already happened, then this is not an issue, but for him to say: 'It is permissible for anyone to transgress my honor', this means that everyone can talk about him, and this is not good… .” [End of quote]
For more information, please refer to Fatwa 84351.
Allaah Knows best.