It is reported that the Prophet ﷺ led the dawn prayer and left out a verse. When he had finished praying, he asked, "Is Ubayy bin Kaab among the people?"Ubayy said, "Messenger of Allah, has such-and-such verse been abrogated, or did you forget it?"He replied, "I forgot it."
ى أن النبي ﷺ صلى الفجر، فترك آية، فلما صلى قال: أفي القوم أبي بن كعب؟ قال أبي: يا رسول الله! نسخت آية كذا وكذا، أو نسيتها؟ قال: نسيتها
Ahmad (15365) and Nasai in Kubra (8183) both narrated it from the hadith of Yahya bin Saeed, from Sufyan, who said, our teacher Salama bin Kuhayl narrated to us, from Dhirr, from Saeed bin Abdul-Rahman bin Abza, from his father, and he mentioned it. Its chain is sahih.There is disagreement about Abdul-Rahman bin Abza. Ibn Hibban mentioned him among the trustworthy members of the generation after the companions, and likewise Bayhaqi (3/212) held the view that his hadith concerning the story of Ubayy is a mursal narration. Meanwhile, Bukhari, Khalifa bin Khayat, Tirmidhi, Yaqub bin Sufyan, Barqi, Daraqutni, and others affirmed that he did have companionship with the Prophet. For this reason, Bukhari included in his Sahih (2255) a report from him that he said, "We used to share the spoils of war with the Prophet ﷺ," and Ibn Saad reported that he was among those who prayed with the Prophet ﷺ.Dhirr is Ibn Abdullah Marhabi, with the meem vocalized with damma and the ra with sukun, a trustworthy and devout narrator among the men relied upon by the community of scholars.Ibn Khuzayma narrated it in his Sahih (1647) through the route of Yahya bin Saeed Qattan with the same chain, except that he added in it, "from Ubayy bin Kaab." Likewise, Abdullah bin Imam Ahmad narrated it (21140), but through another route from Sufyan Thawri with his chain.The hadith is the hadith of Ubayy bin Kaab, and Abdul-Rahman narrated the story according to both versions.Haythami said in Majma (2354), "Ahmad and Tabarani both narrated it from Abdul-Rahman bin Abza, and its men are the men of the Sahih."