If we execute him for disbelief, he is neither washed, shrouded, nor prayed over, nor is he buried among the Muslims. But if we execute him as a prescribed punishment, the ruling is the reverse.
The author’s wording also apparently includes the case of one who falsely accuses the mother of a prophet—may Allah protect us—such as saying that Mary—Allah forbid—was an unchaste woman. Is he to be executed or not?
The answer is that he must be executed. Even if we were to assume that this does not constitute false accusation as such, it amounts to denying the Quran, for Allah Most High says:
“And she who guarded her chastity, so We breathed into her of Our spirit, and made her and her son a sign for all peoples.” [al-Anbiya: 91]
As for the mother of a prophet other than Mary, the correct view is that he is executed for disbelief, because of the immense vileness involved: it suggests that the prophets—far exalted are they above this—were the children of unchaste women.
The apparent meaning of his words also includes the case where someone falsely accuses the wife of a prophet: he would receive eighty lashes, because she falls under the general wording, “a chaste person.” Yet this is a matter of scholarly disagreement, except in the case of Aisha, may Allah be pleased with her: whoever accuses her of that from which Allah exonerated her is a disbeliever, because he denies the Quran. But if he accuses her of something else, or falsely accuses one of the wives of the Prophet, peace and blessings be upon him, or the wife of any prophet whatsoever, then the correct view is that he likewise disbelieves and is executed.
Shaykh al-Islam said: This involves such disparagement and humiliation of the prophet that it cannot be treated lightly. It is more serious than the prohibition on marrying his wives after his death. If Allah has forbidden us to marry the wives of the Messenger, peace and blessings be upon him, after him, out of honor for him and in protection of his marital sanctity, then how could it be defiled in this manner? What is falsely accusing the wives of the prophets if not mockery of the prophets and ridicule of them? Thus, the correct view is that this does not fall within the author’s statement, and it appears that the author did not intend these general formulations.