مُسْنَدُ عُثْمَانَ بْنِ عَفَّانَ رَضِيَ اللَّهُ عَنْهُ
4  
Musnad Uthman ibn Affan
Musnad Ahmad 529
It was narrated from Aban bin `Uthman that He saw a funeral coming. When he saw it he stood up and said. I saw `Uthman doing that and he told me that he saw the Prophet (ﷺ) doing that.
حَدَّثَنَا عَبْد اللَّهِ، حَدَّثَنَا الْحَكَمُ بْنُ مُوسَى، حَدَّثَنَا سَعِيدُ بْنُ مَسْلَمَةَ، عَنْ إِسْمَاعِيلَ بْنِ أُمَيَّةَ، عَنْ مُوسَى بْنِ عِمْرَانَ بْنِ مَنَّاحٍ، عَنْ أَبَانَ بْنِ عُثْمَانَ، أَنَّهُ رَأَى جَنَازَةً مُقْبِلَةً فَلَمَّا رَآهَا قَامَ فَقَالَ رَأَيْتُ عُثْمَانَ يَفْعَلُ ذَلِكَ وَخَبَّرَنِي أَنَّهُ رَأَى النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَفْعَلُهُ‏.‏
Grade: Sahih because of corroborating evidence; this isnad is Da'if because of the weakness of Sa'eed bin Maslamah] (Darussalam)
Reference : Musnad Ahmad 529
In-book reference : Book 4, Hadith 121