What is the response to one who claims that Umar admitted to the Quran being incomplete, based on his statement: "By Allah, were it not that people would say, 'Umar added to the Book of Allah, the Mighty and Exalted,' I would have written it" regarding the verse of stoning, and that Ubayy ibn Ka'b stated that Surat Al-Ahzab was incomplete? And what is the ruling on one who believes that the Quran is incomplete?

Attempting to find fault with the Rightly Guided Caliph Umar (may Allah be pleased with him) is a grave error. He was praised by revelation and by the best of the Salaf. The verse of stoning (rajm) had its recitation abrogated, but its ruling remained. Umar (may Allah be pleased with him) clarified this out of fear that people might go astray by abandoning this obligation, emphasizing the perfection of the Qur'an and that his statement was not an admission of its deficiency. Surah Al-Ahzab was once equal in the number of its verses to Surah Al-Baqarah, and it included the verse of stoning. All of this was removed as part of what was abrogated, meaning by abrogation (naskh). The claim of alteration of the Qur'an by कमी (deficiency) or زيادة (addition) is disbelief that expels one from the fold of Islam, and the people of Islam have reached a consensus on this.