Abu Abdul-Rahman reported,

When Uthman was besieged, he looked down upon them and said, "I implore you, and I implore none but the companions of the Prophet ﷺ. Do you not know that the Messenger of Allah ﷺ said, 'Whoever digs the well of Rumah will have Paradise,' and so I dug it? Do you not know that he said, 'Whoever equips the army of hardship will have Paradise,' and so I equipped it?"They confirmed the truth of what he said.

Azami 9901

Sahih

عن أبي عبد الرحمن

أن عثمان حيث حوصر أشرف عليهم وقال: أنشدكم، ولا أنشد إلا أصحاب النبي ﷺ: ألستم تعلمون أن رسول الله ﷺ قال: من حفر رومة فله الجنة فحفرتها، ألستم تعلمون أنه قال: من جهز جيش العسرة فله الجنة فجهزتها، قال: فصدقوه بما قال.

الأعظمي 9901صحيح
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, "He passed on as if he had never called upon Us for a harm that touched him. Thus"
Numbering
Jami al-Kamil 9901 (2nd edition)
Azami 9901