Musnad AhmadChapter 4Hadith 518
Full Sharh — Musnad Ahmad 518
حَدَّثَنَا زَكَرِيَّا بْنُ عَدِيٍّ، عَنْ عُبَيْدِ اللَّهِ بْنِ عَمْرٍو، عَنْ عَبْدِ اللَّهِ بْنِ مُحَمَّدِ بْنِ عَقِيلٍ، قَالَ قُتِلَ عُثْمَانُ رَضِيَ اللَّهُ عَنْهُ سَنَةَ خَمْسٍ وَثَلَاثِينَ فَكَانَتْ الْفِتْنَةُ خَمْسَ سِنِينَ مِنْهَا أَرْبَعَةُ أَشْهُرٍ لِلْحَسَنِ رَضِيَ اللَّهُ عَنْهُ.
English Translation
It was narrated that ‘Abdullah bin Muhammad bin `Aqeel said:: `Uthman (رضي الله عنه) was killed in 35 AH and the fitnah (turmoil) lasted for five years including four months of al-Hasan`s rule.
Source
Musnad Ahmad(مسند أحمد)
Musnad Uthman ibn Affan
Hadith Number
518