It is narrated from Sayyidah Umm al-Ala' (may Allah be pleased with her), who was one of their (the Ansar's) women who had given the pledge of allegiance to the Prophet (peace and blessings be upon him), that she said: Uthman bin Maz'un (may Allah be pleased with him) passed away, so we wrapped him in his garments. Then the Prophet (peace and blessings be upon him) came, and I said: May Allah have mercy on you, O Abu al-Sa'ib! I bear witness about you that Allah has surely honoured you. The Prophet (peace and blessings be upon him) said: "How do you know? As for him, the certainty (death) has come to him. By Allah, I hope good for him, but I do not know what Allah will do with him." I said: By Allah, I will never again bear witness about anyone. His words silenced me. Then, when I slept, I saw a spring flowing for Uthman bin Maz'un, so I mentioned this to the Messenger of Allah (peace and blessings be upon him), and he (peace and blessings be upon him) said: "That is his deeds."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21800