The Messenger of Allah (peace and blessings be upon him) seeking forgiveness for Zayd bin Amr

Nufayl bin Hisham narrates from his father that his grandfather, Sayyiduna Sa'id bin Zayd (may Allah be pleased with him), asked the Messenger of Allah (peace and blessings be upon him) about his father Zayd bin Amr bin Nufayl, and said: O Messenger of Allah! My father Zayd bin Amr was (a monotheist) just as you saw him and just as news of him reached you; had he lived to see your time, he would certainly have believed in you. Shall I seek forgiveness for him? He (peace and blessings be upon him) said: "Yes, seek forgiveness for him, for he will be raised on the Day of Resurrection as a nation by himself." According to what people related, he was searching for the true religion, and he died while in that search.

It is narrated from Muhammad bin Ja'far bin al-Zubayr that Sayyiduna Umar bin al-Khattab and Sayyiduna Sa'id bin Zayd (may Allah be pleased with them both) said: O Messenger of Allah! Shall we seek forgiveness for Zayd bin Amr? He (peace and blessings be upon him) said: "Yes, seek forgiveness for him, for he will be raised as a nation by himself."

Qays bin Abi Hazim narrates from Sayyiduna Sa'id bin Zayd bin Amr bin Nufayl (may Allah be pleased with him) that he said: "I have seen the time when Umar (may Allah be pleased with him) had (harshly) tied up me and my mother (meaning the mother of Sa'id bin Zayd) because of Islam. And if Mount Uhud were to crumble apart because of what you people have done to Uthman (may Allah be pleased with him), it would be deserving of it."
This hadith is sahih (authentic) on the condition of the two Shaykhs, but they did not record it.