Why was the حد (prescribed punishment) of stoning not mentioned in the Holy Quran despite its enormity, and what is the origin of this حد, given that Allah mentions flogging in the Quran as a حد for adultery? And is the Mahdi a reality despite not being mentioned in the Quran, and does one become an infidel if they do not believe in him?

The Sunnah of the Prophet (peace and blessings be upon him) is a revelation from Allah and is obligatory to follow. Whoever rejects it, sufficing himself with the Qur'an, is in manifest misguidance. Some scholars have even reported a consensus on his disbelief. The Prophet (peace and blessings be upon him) foretold the emergence of those who would deny him, saying: "Adhere to the Qur'an; what you find therein of lawful things, make lawful, and what you find therein of unlawful things, make unlawful."

Ibn Hazm clarified that if we were to limit ourselves to the Qur'an, we would not know the details of many acts of worship and rulings, such as the number of rak'ahs in prayer, how to pay Zakat and perform Hajj, and the rulings on hudud (punishments) and transactions, among others. He stated that whoever says, "We only take what we find in the Qur'an," would be a disbeliever by the consensus of the Ummah.

Branching from this is the establishment of the punishment of stoning for the married fornicator by the continuously transmitted Sunnah and the consensus of scholars, as well as the establishment of the appearance of the Mahdi at the end of time by authentic hadiths.