[Hajj on Behalf of a Sinner (Fāsiq) and Reciting the Qur’an for Him]

Answer—and Allah grants success: Performing Hajj as a proxy on behalf of a sinner is permissible, for nothing prevents it except his sinfulness, and that is not an impediment to performing it but rather to its acceptance, in His saying: “Indeed, Allah only accepts from the righteous.” [al-Māʾidah:27]
Therefore, if the sinner bequeaths that Hajj be performed on his behalf, there is no objection to performing Hajj for him for a fee, for he has only bequeathed obedience to Allah and a righteous deed, and the most that can be said is that it might not be accepted from him.
Likewise, if the sinner bequeaths that charity be distributed to the poor, it is permissible for a believer to distribute it on his behalf as a proxy to the poor. Similarly, if he orders a mosque to be built or the like among types of righteousness, it is permissible for a believer to act as his proxy in that. These and similar acts are deeds of goodness, and the most that can be said is that Allah Most High might not accept them from him.
As for the one striving to carry that out, he has the reward for his deed and his striving, in His saying: “So their Lord responded to them, ‘Indeed, I do not allow to be lost the work of [any] worker among you, whether male or female.’” [Āl ʿImrān:195]. And His saying: “For it [i.e., every soul] is what it has earned, and against it is what it has incurred.” [al-Baqarah: 286]
Yes—there has come a prohibition on seeking forgiveness for the polytheists, on the grounds that they are enemies of Allah and inhabitants of Hellfire, in His saying: “It is not for the Prophet and those who have believed to ask forgiveness for the polytheists—even if they were relatives—after it has become clear to them that they are companions of the Hellfire. And the request of Abraham for forgiveness for his father was only because of a promise he had made to him; but when it became clear to him that he was an enemy to Allah, he disassociated himself from him …” [al-Tawbah: 113–114]
From this verse it has been taken that it is not permissible to supplicate for Allah’s enemies with good of the Hereafter. Accordingly, a believer regarding the sinner should not seek forgiveness for him nor supplicate for him with the good of the Hereafter.
As for reciting the Qur’an, it has two considerations:
If by its recitation one intends to seek nearness to Allah on behalf of the deceased sinner—asking mercy for him, pardon for him, forgiveness of his sins, and the like of the good of the Hereafter—then it is not permissible to recite it with that intention, due to the cited evidence prohibiting supplication for Allah’s enemies.
If, however, one intends by recitation merely the execution of the bequest, then apparently there is no objection to that, for reciting the Qur’an is obedience to Allah. And the most that can be said—as previously mentioned—is that the deceased sinner’s act which he commissioned and bequeathed may not be accepted from him.
If it be said: The deceased bequeathed the recitation intending thereby nearness to Allah and seeking by it forgiveness and mercy, etc.
We say: The deceased has his intention, seeking of nearness, and will. As for the reciter, he neither sought nearness nor supplicated nor sought forgiveness for the sinner; he only recited the Qur’an with the sinner’s intention in mind. Thus the intention and seeking of nearness are from the sinner, while the recitation is from the reciter—so the prohibited matter has not occurred, and what did occur is obedience to Allah.
Yes—there is a third case: that the recitation of the Qur’an be directed “to the soul” of the sinner. Reciting the Qur’an with this intention is not permissible, because its purpose in that case is to seek good for the sinner and to supplicate on his behalf—and that, as stated, is prohibited.
It is proper to avoid what appears to magnify and show allegiance to a sinful deceased person. Such acts include following his funeral, praying over him, gathering to recite the Qur’an “to his soul,” and building over his grave—due to His saying regarding the hypocrites: “And do not ever pray over any of them who has died, nor stand at his grave. Indeed, they disbelieved in Allah and His Messenger and died while defiantly disobedient.” [al-Tawbah:84]
It is permissible to take a fee for reciting the Qur’an, by the proof of the report of the expedition in which they performed ruqyah for the chief of a people with the Qur’an for a flock of sheep; they informed the Messenger of Allah (May Allah bless him and his family and grant them peace), and he approved them. This story is well-known.
Also, this story indicates the permissibility of treating a sinner with ruqyah from the Qur’an—as well as a dhimmī—and taking a fee for that.
Furthermore, in the marginal notes on Sharḥ al-Azhār it is stated: As for the sinful, if the recitation is at his grave or “Ê to his soul,” it is Ê not Ê permissible to take a fee for that. But if it is “to the soul” of the Prophet (May Allah bless him and his family and grant them peace) or the People of the Cloak (Ahl al-Kisāʾ) or other virtuous ones, that is Ê permissible and Ê taking a Ê fee is Ê lawful—analogous to performing Hajj on behalf of another. End.
Source : Min Thimār al-ʿIlm wa al-Ḥikmah vol.1