Hadithcore
Musnad Ahmad, 407
hasan· Darussalam

Abu Sahlah narrated that `Uthman (رضي الله عنه) said, on the Day of the House when he was besieged. The Messenger of Allah (ﷺ) gave me advice and I promised to comply with it, so I shall bear it with patience. Qais said:

People thought that it was that day (when he was killed).

حَدَّثَنَا وَكِيعٌ، عَنْ إِسْمَاعِيلَ بْنِ أَبِي خَالِدٍ، قَالَ قَالَ قَيْسٌ فَحَدَّثَنِي أَبُو سَهْلَةَ، أَنَّ عُثْمَانَ، رَضِيَ اللَّهُ عَنْهُ قَالَ يَوْمَ الدَّارِ حِينَ حُصِرَ إِنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ عَهِدَ إِلَيَّ عَهْدًا فَأَنَا صَابِرٌ عَلَيْهِ قَالَ قَيْسٌ فَكَانُوا يَرَوْنَهُ ذَلِكَ الْيَوْمَ‏.‏

References1 variant
In-Book Reference
Book 4, Hadith 9