What is the ruling on donating organs?

The questioner : In Islam, and even in the noble hadith, it is stated that Muslims in their love, mercy, and compassion for one another are like a single body. If we show mercy to one another while we are alive, and if I have two dirhams and I like to divide them between you and me if you do not have any, and if you have the same situation, why should not this mercy extend to what comes after, to what is after this worldly life? In other words, I heard a comment from several shaykhs that it is not permissible to donate the eye, it is not permissible to donate the cornea, it is not permissible to donate the kidney; because the wound of the dead is like the wound of the living, and breaking the bone of the dead is like breaking the bone of the living... I, of course, am not very knowledgeable in religion, but I say: why do the mujtahids not correlate or agree upon the constants in this worldly life and the constants in the life after this worldly life...?

The Shaykh : The reason—may Allah bless you—is several matters, the most important of which is that the rulings of the Hereafter are not measured by the rulings of this world; for example, he (peace be upon him) said: . I think the hadith is clear to you and does not need explanation; so as long as the dead person’s connection to this world has been severed, he has no right to dispose of any part of his body after his death except by the permission of his Lord. This permission, first of all and obviously, is absent and does not exist. And none of those whom you call mujtahids can provide you with a text from Allah or His Messenger that it is permissible for a Muslim to dispose of his body after his death as was his case before his death. Second and finally: in the sentence you mentioned during your speech, it is important to know that this is not the speech of people, this is the speech of the master of people, the Messenger (may Allah’s prayers and blessings be upon him); where he used to say: . Therefore, a Muslim has no right to dispose of his body by a bequest he issues while he is alive; because it contradicts the bequest of the Messenger (peace be upon him) in his saying: .
Then there is a third thing we can include in the group of the two previous proofs, but before mentioning this third thing, I want to summarize what has passed of the two previous proofs. The first proof is that we do not have a text from the Wise Lawgiver that justifies us disposing of our bodies after our death and our work has been severed. The second proof is higher than this; in addition to the fact that there is no proof that allows us this voluntary act, there is a proof that prevents us from such a voluntary act; and that is his saying (peace be upon him): . We come to the second proof... that the Messenger (peace be upon him), as in the authentic hadith: . Look here, it seems there is an eloquent point; he commanded charity, but one does not give charity with what involves mutilation, . A Muslim bequeaths that they wound his eye after his death so that they can take the cornea and implant it in the eye of a blind person or a one-eyed person or something similar, so this is mutilation, and the Wise Lawgiver prohibited that. And if a person thinks, he will find many and very many things; among them he (peace be upon him) said: . So when we want to perform an operation on this dead person, what do we do? Instead of taking him to the graveyard as soon as possible, we put him on the autopsy table, and we see which doctor will perform...