Um Al-ʿAla an Ansari woman who had given a pledge of allegiance to Messenger of Allah ﷺ told me:, "The Muhajirln (emigrants) were distributed amongst us by drawing lots, and we got ʿUthman bin Maz'un in our share. We made him stay with us in our house. Then he suffered from a disease which proved fatal. When he died and was given a bath and was shrouded in his clothes. Messenger of Allah ﷺ came, I said, (addressing the dead body), 'O Aba As-Sa'ib! May Allah be Merciful to you! I testify that Allah has honored you.' Messenger of Allah ﷺ said, 'How do you know that Allah has honored him?" I replied, 'Let my father be sacrificed for you, O Messenger of Allah ﷺ! On whom else shall Allah bestow. His honor?' Messenger of Allah ﷺ said, 'As for him, by Allah, death has come to him. By Allah, I wish him all good (from Allah). By Allah, in spite of the fact that I am Messenger of Allah ﷺ, I do not know what Allah will do to me.", Um Al-ʿAla added, "By Allah, I will never attest the righteousness of anybody after that."  

أَنَّ أُمَّ الْعَلاَءِ امْرَأَةً مِنَ الأَنْصَارِ بَايَعَتْ رَسُولَ اللَّهِ ﷺ أَخْبَرَتْهُ أَنَّهُمُ اقْتَسَمُوا الْمُهَاجِرِينَ قُرْعَةً قَالَتْ فَطَارَ لَنَا عُثْمَانُ بْنُ مَظْعُونٍ وَأَنْزَلْنَاهُ فِي أَبْيَاتِنَا فَوَجِعَ وَجَعَهُ الَّذِي تُوُفِّيَ فِيهِ فَلَمَّا تُوُفِّيَ غُسِّلَ وَكُفِّنَ فِي أَثْوَابِهِ دَخَلَ رَسُولُ اللَّهِ ﷺ فَقُلْتُ رَحْمَةُ اللَّهِ عَلَيْكَ أَبَا السَّائِبِ فَشَهَادَتِي عَلَيْكَ لَقَدْ أَكْرَمَكَ اللَّهُ فَقَالَ رَسُولُ اللَّهِ ﷺ وَمَا يُدْرِيكِ أَنَّ اللَّهَ أَكْرَمَهُ فَقُلْتُ بِأَبِي أَنْتَ يَا رَسُولَ اللَّهِ فَمَنْ يُكْرِمُهُ اللَّهُ فَقَالَ رَسُولُ اللَّهِ ﷺ أَمَّا هُوَ فَوَاللَّهِ لَقَدْ جَاءَهُ الْيَقِينُ وَاللَّهِ إِنِّي لأَرْجُو لَهُ الْخَيْرَ وَوَاللَّهِ مَا أَدْرِي وَأَنَا رَسُولُ اللَّهِ مَاذَا يُفْعَلُ بِي فَقَالَتْ وَاللَّهِ لاَ أُزَكِّي بَعْدَهُ أَحَدًا أَبَدًا  

Regarding the above narration, The Prophet ﷺ said, "I do not know what Allah will do to him (Uthman bin Maz'un)." Um Al-ʿAla said, "I felt very sorry for that, and then I slept and saw in a dream a flowing spring for ʿUthman bin Maz'un, and told Messenger of Allah ﷺ of that, and he said, "That flowing spring symbolizes his good deeds."  

وَقَالَ مَا أَدْرِي مَا يُفْعَلُ بِهِ قَالَتْ وَأَحْزَنَنِي فَنِمْتُ فَرَأَيْتُ لِعُثْمَانَ عَيْنًا تَجْرِي فَأَخْبَرْتُ رَسُولَ اللَّهِ ﷺ فَقَالَ ذَلِكَ عَمَلُهُ