[How One Who Gained Wealth from Trading in Narcotics Can Find a Way Out]

The answer—and Allah is the granter of success—is that what is known among the scholars and settled with them is that when Allah has forbidden a thing, He has forbidden its price. Among the evidences for this is what is narrated from the Prophet—May Allah bless him and his family and grant them peace—who said: “Allah cursed the Jews: when Allah forbade their fat, they melted it, sold it, and consumed its price,” or as he said. There are also narrations on the prohibition of the price of a dog, wine, and other things.
In truth, the proof that indicates a thing’s prohibition, by itself, indicates the prohibition of its price. The scholars of legal theory call the proof that indicates this “the general purport (ʿumūm al-muqtaḍā).” Thus, in the likes of “Prohibited to you are dead animals …” [Al-Mā’idah:3], they say that this, by the general purport, indicates the prohibition of eating, selling, buying, possessing, and all other forms of benefiting that could occur.
By what we have mentioned, it becomes clear that it is not permissible to consume wealth obtained from the price of what Allah Most High has forbidden, nor to take possession of it, nor to benefit from it.
As for the question of how to rid oneself of its consequences: Know that Allah Most High has made the path of repentance easy for His servants and facilitated it, as a mercy to them. He, Glorified is He, said in explaining the repentance of those who consume usury: “So whoever has received an admonition from his Lord and desists may have what is past, and his affair rests with Allah; but whoever returns—those are the companions of the Fire; they will abide therein eternally.” [Al-Baqarah:275]. Thus Allah, Exalted is He, pardoned the usury-eaters for what they had previously taken of usury if they repent and desist from taking usury.
He did not obligate them to give in charity what was in their hands of wealth, nor to return it to its owners; rather, He commanded them to abandon what remains with people of usurious increase and to take only their principals. He, Exalted, said: “O you who have believed, fear Allah and give up what remains [due to you] of usury …” [Al-Baqarah:278], and “But if you repent, you may have your principal—you do no wrong, nor are you wronged.” [Al-Baqarah:279].
On that basis we say: This man who was trading in narcotics has, in his repentance, the same ruling as the usury-eaters when they repent. If this man repented when the admonitions of the preachers reached him and he ceased his unlawful trade, then he may keep what is past and his affair is with Allah; he is not obliged to give in charity what he had acquired before repentance, and sincere repentance with remorse is sufficient for his deliverance, if Allah wills. This is what appears to me. And Allah Most High knows best. Praise be to Allah, Lord of the worlds, and may Allah bless Prophet Muhammad and his family, and grant them peace.
Clarification
A man who trades in narcotics and the like among the various prohibitions—sincere repentance and ceasing the act suffice him; he need not return the monies to their owners nor give them in charity. We only say this because he was taking the prices with their owners’ permission and consent; they permitted him to take, consume, dispose of, and take possession of [those monies].
Thus the trader, in that case, has fallen short only with respect to Allah’s right—by partaking of what was forbidden to him. Hence, repentance to Allah Most High concerning what he fell short in regarding His right is sufficient; he need not seek release from the creatures from whom he took those prohibited monies, for they had permitted them to him and authorized him to take them, dispose of them, and take possession of them.
Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.2