What is the ruling on one who donates one of his organs after his death?

Question : Is it permissible to make a bequest to donate one of the organs after death?

Answer : Did you hear the one seeking assistance? Yes, it is not permissible for a person to donate one of his organs, neither in his lifetime nor after his death. As for in his lifetime, it is apparent, because if he donates one of his organs, there is harm in that for him. Indeed, Allah the Exalted did not create the repeated organs except for a benefit. Let us take the kidney as an example. If a person donates his kidney to someone in his lifetime, we say: This is forbidden for you, because you do not have the right to cut off a finger from your fingers, let alone a kidney from your two kidneys.
If you donate this kidney, how many do you have left? Yes, good. And if he has three kidneys? If a person has three kidneys, he cuts off one. In my opinion, this is not possible, but let us suppose the case with the two kidneys. If he donates one kidney, one remains with him, and this one will have to do the work alone, instead of the work being divided between it and its counterpart. The work will be difficult for it, and it will be damaged soon. Because with the amount of work and strain, the body is destroyed. So he becomes the cause of harm to himself. Perhaps this remaining kidney will fail and he will perish, whereas if he had the first one that was harmed by it, he would have been safe with it. This is one point.
Second, if he donates the kidney and it is transplanted into another person, do we guarantee one hundred percent that the operation will succeed? No, often the operation fails, so we commit a forbidden act with certainty for a matter that is beneficial, but only by way of conjecture and not by way of certainty.
And after death, it is also not permissible for a person to donate it. So it is not permissible to bequeath one’s kidney to a person after his death. Why? Because of the saying of the Prophet (peace and blessings be upon him): This indicates that the dead person is respected like the living person is respected. So it is not permissible to bequeath one’s kidney or one’s horn to anyone after death, because ownership belongs to Allah, and the person is commanded to preserve himself. Indeed, a man’s obligatory prayers are dropped from him to preserve his health. Have you seen the sick person for whom using water is harmful? What does he do when it is time for prayer? He performs dry ablution with clean earth, as it is obligatory, to preserve his health. So how can a person do something that destroys his health if he is alive, or violates his sanctity if he is dead? For this reason, the Hanbali jurists stated and mentioned in the book of funerals that it is not permissible for a person to bequeath one of his organs to anyone after his death, and that if he bequeathed it, the bequest would not be executed.