(46) باب مَقْدَمِ النَّبِيِّ صلى الله عليه وسلم وَأَصْحَابِهِ الْمَدِينَةَ
Narrated 'Um Al-`Ala:
An Ansari woman who gave the pledge of allegiance to the Prophet (ﷺ) that the Ansar drew lots concerning the dwelling of the Emigrants. `Uthman bin Maz'un was decided to dwell with them (i.e. Um Al-`Ala's family), `Uthman fell ill and I nursed him till he died, and we covered him with his clothes. Then the Prophet (ﷺ) came to us and I (addressing the dead body) said, "O Abu As-Sa'ib, may Allah's Mercy be on you! I bear witness that Allah has honored you." On that the Prophet (ﷺ) said, "How do you know that Allah has honored him?" I replied, "I do not know. May my father and my mother be sacrificed for you, O Allah's Messenger (ﷺ)! But who else is worthy of it (if not `Uthman)?" He said, "As to him, by Allah, death has overtaken him, and I hope the best for him. By Allah, though I am the Apostle of Allah, yet I do not know what Allah will do to me," By Allah, I will never assert the piety of anyone after him. That made me sad, and when I slept I saw in a dream a flowing stream for `Uthman bin Maz'un. I went to Allah's Messenger (ﷺ) and told him of it. He remarked, "That symbolizes his (good) deeds."
Reference: Sahih al-Bukhari 3929
In-book reference: Book 63, Hadith 155
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 5, Book 58, Hadith 266