Umar bin Khattab and I asked the Prophet ﷺ about Zayd bin Amr bin Nufayl, and he said, "He will come on the Day of Resurrection as a nation by himself."
سألت أنا وعمر بن الخطاب يعني النبي ﷺ عن زيد بن عمرو بن نفيل، فقال: يأتي يوم القيامة أمة وحده.
Ibn Abu Asim reported it in al-Ahad wal-Mathani (775) from Muhammad bin Ismail (that is, Bukhari), who said, Ibn Abu Uways narrated to us, who said, Ibn Abu Zinad (that is, Abdul-Rahman) narrated to us, from Hisham bin Urwa, from his father, that Saeed bin Zayd bin Amr bin Nufayl said, and then he related it. Its isnad is hasan on account of Ibn Abu Uways, who is Ismail bin Abdullah bin Uways al-Madani, about whom there is disagreement, except that his hadith is judged hasan when it has a firm basis elsewhere, and this hadith is one such case. Zayd bin Amr bin Nufayl was the cousin of Umar bin Khattab bin Nufayl.As for what was narrated by Nufayl bin Hisham bin Saeed bin Zayd bin Amr bin Nufayl al-Adawi, of the Adi clan of Quraysh, from his father, from his grandfather, that Zayd bin Amr and Waraqa bin Nawfal set out searching for the true religion, until they came to a monk in Mosul. He said to Zayd bin Amr, "Where have you come from, camel rider?" He said, "From the House of Ibrahim." He said, "And what are you seeking?" He said, "I am seeking the true religion." He said, "Turn back, for the one you are seeking is about to appear in your own land." As for Waraqa, he became a Christian. Zayd said, "As for me, Christianity was presented to me, but it did not suit me." So he turned back, saying,"Here I am truly, truly, in devotion and servitude, I seek righteousness, not personal advantage, and is one who emigrates like one who says, I believe in what Ibrahim believed in?"And he would say,"I submit myself to You, O Allah, as one humbled and submissive, whatever burden You place on me, I will bear it."Then he would prostrate himself. He said, and his son came to the Prophet ﷺ and said, "Messenger of Allah, my father was as you have seen and as has reached you, so ask forgiveness for him." He said, "Yes, for he will be raised on the Day of Resurrection as a community unto himself."Abu Dawud Tayalisi narrated it (231), and this wording is his, as did Ahmad (1648), Hakim (3/439), and Bayhaqi in Dalail (2/123-124), all of them through the route of Masudi, from Nufayl bin Hisham, and then he related it. So its isnad is daif. Masudi is Abdul-Rahman bin Abdullah, whose memory became confused, and Nufayl and his father Hisham are both unknown.