What is the basis for disbelief in the hadith mentioned in Ibn Kathir's Tafsir regarding the Almighty's saying, "And do not marry those whom your fathers married..."? And why did the Prophet, peace and blessings be upon him, not consider this act incestuous fornication? And can this be analogized to one who marries five women simultaneously or a woman who marries two men simultaneously?

Modern scholars have interpreted the saying that whoever marries his father's wife should be killed as meaning that the intention is for one who does so considering it permissible, as was done in the جاهلية (pre-Islamic era). In this case, he would be an apostate, so the punishment is not a حد (prescribed punishment) for adultery, but for apostasy.

Al-Shawkani was of the view that the hadith indicates the permissibility for the Imam to order the killing of anyone who violates the definitive tenets of Sharia, such as marrying one's father's wife. However, this is on the condition that the perpetrator considers this forbidden act permissible, an act whose prohibition is established by definitive texts, not merely someone who married her out of ignorance or the like. This can be analogized to anyone who considers a definitively forbidden act permissible while knowing its prohibition, such as murder or drinking alcohol.