Praise be to Allah.
Repentance means turning back to Allah and turning from disobedience to obedience, and restoring people’s rights. We have to understand that repentance is obligatory for every Muslim as Allah says (interpretation of the meaning):
“O you who believe! Turn to Allah with sincere repentance.”
Allah rejoices over the repentance of the penitent even though He has no need of their obedience. He tells us that He loves the penitent, as He says (interpretation of the meaning):
“Truly, Allah loves those who turn unto Him in repentance and loves those who purify themselves.”
The one who transgresses against people transgresses against either their material rights or their intangible rights. In either case he is transgressing against the rulings of sharee’ah (Islamic law).
Based on this, he needs to repent sincerely concerning that which is between him and his Lord, and he needs to restore people’s rights. With regard to intangible rights, the way to do it – besides repenting sincerely – is to pray for forgiveness for them and make du’a (supplicate) for them, if they did not know that he had wronged them. But if he backbit about them, and they got to hear about it, then he must also apologize to them and ask them to forgive him.
With regard to material rights, repentance between him and his Lord is not sufficient, and making du’a (supplicating) for the person is also not sufficient. Rather he must restore these material rights and return things to their owners. If they are not there then he must return it to their heirs.
If he is unable to return it because he does not know who the owner is, then he should give it in charity on his behalf. If he is unable to do this because he is poor, then there is the hope that if his repentance is sincere, then Allah will pay it off on his behalf so that the owner will be pleased with that, and there is the hope, insha Allah, that Allah will not punish him in the grave or in the Hereafter.
But if he does not repent, then Allah will restore the person’s rights from the hasanat (good deeds) of the transgressor; if his hasanat are all used up then some of the sayyiat (bad deeds) of the one who was wronged will be taken and added to the burden of the transgressor. This is true bankruptcy, in addition to the punishment that Allah will inflict on him because of his transgression against sharee’ah (sacred law).
It says in Rawdat al-Talibeen:
If there is any financial right that is connected to the sin, such as withholding zakah (poor-due), seizing by force or crimes against people’s wealth, then in addition to this – i.e., repentance – he must also discharge the duty of paying zakah or returning people’s wealth if it is still there, or by giving something of equal value if it is no longer there, or he may ask the one to whom it rightfully belongs to let him off.
If the one who was transgressed against was not aware of it, he should be told and the transgressor should ensure that what is rightfully his reaches him. If he has died then he should give it to his heir. If he has no heir and nothing is known of him then he should give it to the qadhi (jusdge) whose conduct is good and who is known for his religious commitment. If this is not possible then he should give it in charity on his behalf to the poor, with the intention of compensating him if he finds him.
If he is in financial difficulty, then we think that he should form the intention to pay it back when he can afford it. If he dies before he is able to afford it, then we hope that he will be forgiven by Allah’s grace.
Al-Nawawi said: I say: The apparent meaning of the Sunnah (prophetic teachings) is that wrongdoing is still attached to him until he pays it back, even if he dies when he is in financial difficulty and is unable to pay it back, if he persisted in not intending to pay it back.
But if he had taken a loan in a permissible manner, but he remained unable to pay it off until he died, or he destroyed something by mistake and was unable to pay compensation for it until he died, then it seems that in this case he will not be required to pay for it in the Hereafter, because he did not commit a sin, and we hope that Allah will compensate the owner.
With regard to backbiting, if news of it does not reach the victim, then I have read in the fatwas of al-Hinati that it is sufficient for him to regret it and pray for forgiveness. If news of it did reach him, then the proper way is to contact the victim and ask him to forgive him. If he is not able to do this because he has died or he is away, then he should pray for forgiveness for him. There is no point in seeking forgiveness from the heirs. This is the view of al-Hinati. End quote.
And Allah knows best.