Ayesha reported,

The Messenger of Allah ﷺ sent for Uthman bin Affan, and the Messenger of Allah ﷺ turned toward him. When we saw the Messenger of Allah ﷺ, we glanced at one another. Among the last words he spoke to him was that he tapped his shoulder and said, "Uthman, Allah عز وجل may clothe you in a shirt. If the hypocrites seek to strip it from you, do not remove it until you meet me. Uthman, Allah may clothe you in a shirt, and if the hypocrites seek to strip it from you, do not remove it until you meet me," repeating it three times.I said to her, "Umm Muiminin, where was this account from you all this time?"She replied, "By Allah, I forgot it and never recalled it."He said, So I informed Muawiya bin Abu Sufyan of this, but he was not satisfied with what I had told him until he wrote to Umm Muiminin asking her to write it down for him, so she wrote him a letter about it.

Azami 9907

Sahih

عن عائشة قالت

أرسل رسول الله ﷺ إلى عثمان بن عفان، فأقبل عليه رسول الله ﷺ، فلما رأينا رسول الله ﷺ أقبلت إحدانا على الأخرى، فكان من آخر كلام كلمه أن ضرب منكبه، وقال: يا عثمان، إن الله عز وجل عسى أن يلبسك قميصا، فإن أرادك المنافقون على خلعه فلا تخلعه حتى تلقاني، يا عثمان، إن الله عسى أن يلبسك قميصا فإن أرادك المنافقون على خلعه فلا تخلعه حتى تلقاني ثلاثا. فقلت لها: يا أم المؤمنين فأين كان هذا عنك؟ قالت: نسيته والله فما ذكرته. قال: فأخبرته معاوية بن أبي سفيان، فلم يرض بالذي أخبرته حتى كتب إلى أم المؤمنين أن اكتبي إلي به فكتبت إليه به كتابا.

الأعظمي 9907صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Virtues of the Companions and reports about them
Chapter
Virtues of Uthman bin Affan and reports about him
Section
His saying, "Uthman will be killed unjustly"
Numbering
Jami al-Kamil 9907 (2nd edition)
Azami 9907