Umm Ala reported,

I pledged allegiance to the Prophet ﷺ. She informed him that the Emigrants drew lots, and Uthman bin Mazun fell to our share, so we lodged him in our home. He fell ill with the sickness from which he died. When he died and was washed and shrouded in his garments, the Messenger of Allah ﷺ entered.I said, "May Allah's mercy be upon you, Abu Saaib. My testimony concerning you is that Allah has honored you."The Prophet ﷺ said, "How do you know that Allah has honored him?"I said, "May my father be ransom for you, Messenger of Allah. Whom else would Allah honor?"He said, "As for him, certainty has come to him. By Allah, I hope good for him. By Allah, though I am the Messenger of Allah, I do not know what will be done with me."She said, "By Allah, I will never declare anyone pure after him."

Azami 157

Sahih

عن أم العلاء- امرأة من الأنصار

بايعت النبي ﷺ- أخبرته أنه اقتسم المهاجرون قرعة، فطار لنا عثمان بن مظعون، فأنزلناه في أبياتنا، فوجع وجعه الذي توفي فيه، فلما توفي وغسل وكفن في أثوابه دخل رسول الله ﷺ فقلت: رحمة الله عليك أبا السائب، فشهادتي عليك، لقد أكرمك الله. فقال النبي ﷺ: وما يدريك أن الله أكرمه؟ فقلت: بأبي أنت يا رسول الله، فمن يكرمه الله؟ فقال: أما هو فقد جاءه اليقين، والله إني لأرجو له الخير، والله ما أدري وأنا رسول الله ما يفعل بي. قالت: فوالله لا أزكي أحدا بعده أبدا.

الأعظمي 157صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Faith
Chapter
Qualities of faith
Section
Fear and piety
Numbering
Jami al-Kamil 157 (2nd edition)
Azami 157