Narrated Marwan bin Al-Hakam:

'Uthman bin 'Affan was afflicted with severe nose-bleeding in the year when such illness was prevelant and that prevented him from performing Hajj, and (because of it) he made his will. A man from Quraish came to him and said, "Appoint your successor." 'Uthman asked, "Did the people name him? (i.e. the successor) the man said, "Yes." Uthman asked, "Who is that?" The man remained silent. Another man came to 'Uthman and I think it was Al-Harith. He also said, "Appoint your successor." 'Uthman asked, "Did the people name him?" The man replied "Yes." 'Uthman said, "Who is that?" The man remained silent. 'Uthman said, "Perhaps they have mentioned Az-Zubair?" The man said, "Yes." 'Uthman said, "By Him in Whose Hands my life is, he is the best of them as I know, and the dearest of them to Allah's Apostle ."

حَدَّثَنَا خَالِدُ بْنُ مَخْلَدٍ، حَدَّثَنَا عَلِيُّ بْنُ مُسْهِرٍ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، قَالَ أَخْبَرَنِي مَرْوَانُ بْنُ الْحَكَمِ، قَالَ أَصَابَ عُثْمَانَ بْنَ عَفَّانَ رُعَافٌ شَدِيدٌ سَنَةَ الرُّعَافِ، حَتَّى حَبَسَهُ عَنِ الْحَجِّ وَأَوْصَى، فَدَخَلَ عَلَيْهِ رَجُلٌ مِنْ قُرَيْشٍ قَالَ اسْتَخْلِفْ. قَالَ وَقَالُوهُ قَالَ نَعَمْ. قَالَ وَمَنْ فَسَكَتَ، فَدَخَلَ عَلَيْهِ رَجُلٌ آخَرُ ـ أَحْسِبُهُ الْحَارِثَ ـ فَقَالَ اسْتَخْلِفْ. فَقَالَ عُثْمَانُ وَقَالُوا فَقَالَ نَعَمْ. قَالَ وَمَنْ هُوَ فَسَكَتَ قَالَ فَلَعَلَّهُمْ قَالُوا الزُّبَيْرَ قَالَ نَعَمْ. قَالَ أَمَا وَالَّذِي نَفْسِي بِيَدِهِ إِنَّهُ لَخَيْرُهُمْ مَا عَلِمْتُ، وَإِنْ كَانَ لأَحَبَّهُمْ إِلَى رَسُولِ اللَّهِ ﷺ.