Ibn al-Aas and Zayd bin Thabit were writing out copies of the Quran, and they came upon this verse. Zayd said, "I heard the Messenger of Allah ﷺ say, 'When the old man and the old woman commit adultery, stone them without fail.'"Umar said, "When this was revealed, I went to the Messenger of Allah ﷺ and said, 'Let me write it down for you.'"Shuba said, "It seemed he disliked that."Umar said, "Don't you see that if an older man is not married he is only flogged, while if a young man commits adultery and is married he is stoned?"
كان ابن العاص وزيد بن ثابت يكتبان المصاحف، فمروا على هذه الآية، فقال زيد: سمعت رسول الله ﷺ يقول: الشيخ والشيخة إذا زنيا فارجموهما البتة فقال عمر: لما أنزلت هذه أتيت رسول الله ﷺ، فقلت: أكتبنيها. قال شعبة: فكأنه كره ذلك، فقال عمر: ألا ترى أن الشيخ إذا لم يحصن جلد، وأن الشاب إذا زنى وقد أحصن رحم.
Ahmad narrated it (21596) from Muhammad bin Jafar, who said, Shuba narrated to us, from Qatada, from Yunus bin Jubayr, from Kathir bin Salt, who said, and then he related it.So perhaps his statement, "The old man and the old woman, if they commit adultery..." is part of the revelation of the sunnah, and not part of the revelation of the Quran.Nasai narrated it in Sunan al-Kubra (7148), and Bayhaqi (8/211), both from the hadith of Abdullah bin Awn, from Muhammad bin Sirin, who said, I was informed by the nephew of Kathir bin Salt, who said, "We were with Marwan," meaning Ibn Hakam, "and among us was Zayd bin Thabit. Zayd said, 'We used to recite, "The old man and the old woman, if they commit adultery, stone them both without exception."' Marwan said, 'Shall we not put it in the Quran?' He said, 'No. Do you not see that the two young ones are stoned?'"There is a break in its chain of transmission.