ʿUthman bin ʿAffan 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." ʿUthman asked, "Did the people name him? (i.e. the successor) the man said, "Yes." ʿUthman asked, "Who is that?" The man remained silent. Another man came to ʿUthman and I think it was Al-Harith. He also said, "Appoint your successor." ʿUthman asked, "Did the people name him?" The man replied "Yes." ʿUthman said, "Who is that?" The man remained silent. ʿUthman said, "Perhaps they have mentioned Az-Zubair?" The man said, "Yes." ʿUthman said, "By Him in Whose Hands my life is, he is the best of them as I know, and the dearest of them to Messenger of Allah ﷺ ."  

عَنِ الْحَجِّ وَأَوْصَى فَدَخَلَ عَلَيْهِ رَجُلٌ مِنْ قُرَيْشٍ قَالَ اسْتَخْلِفْ قَالَ وَقَالُوهُ قَالَ نَعَمْ قَالَ وَمَنْ فَسَكَتَ فَدَخَلَ عَلَيْهِ رَجُلٌ آخَرُ أَحْسِبُهُ الْحَارِثَ 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  

While I was with ʿUthman, a man came to him and said, "Appoint your successor." ʿUthman said, "Has such successor been named?" He replied, "Yes, Az-Zubair." ʿUthman said, thrice, "By Allah! Indeed you know that he is the best of you."  

سَمِعْتُ مَرْوَانَ كُنْتُ عِنْدَ عُثْمَانَ أَتَاهُ رَجُلٌ فَقَالَ اسْتَخْلِفْ قَالَ وَقِيلَ ذَاكَ قَالَ نَعَمْ الزُّبَيْرُ قَالَ أَمَا وَاللَّهِ إِنَّكُمْ لَتَعْلَمُونَ أَنَّهُ خَيْرُكُمْ ثَلاَثًا  

The Prophet ﷺ said, "Every prophet used to have a Hawari (i.e. disciple), and my Hawari is Az-Zubair bin Al-ʿAwwam."  

قَالَ النَّبِيُّ ﷺ إِنَّ لِكُلِّ نَبِيٍّ حَوَارِيًّا وَإِنَّ حَوَارِيَّ الزُّبَيْرُ بْنُ الْعَوَّامِ  

During the battle of Al-Ahzab, I and ʿUmar bin Abi-Salama were kept behind with the women. Behold! I saw (my father) Az-Zubair riding his horse, going to and coming from Bani Quraiza twice or thrice. So when I came back I said, "O my father! I saw you going to and coming from Bani Quraiza?" He said, "Did you really see me, O my son?" I said, "Yes." He said, "Messenger of Allah ﷺ said, 'Who will go to Bani Quraiza and bring me their news?' So I went, and when I came back, Allah's Apostle mentioned for me both his parents saying, "Let my father and mother be sacrificed for you."'  

أَوَهَلْ رَأَيْتَنِي يَا بُنَىَّ قُلْتُ نَعَمْ قَالَ كَانَ رَسُولُ اللَّهِ ﷺ قَالَ مَنْ يَأْتِ بَنِي قُرَيْظَةَ فَيَأْتِينِي بِخَبَرِهِمْ فَانْطَلَقْتُ فَلَمَّا رَجَعْتُ جَمَعَ لِي رَسُولُ اللَّهِ ﷺ أَبَوَيْهِ فَقَالَ فِدَاكَ أَبِي وَأُمِّي  

On the day of the battle of Al-Yarmuk, the companions of the Prophet ﷺ said to Az-Zubair, "Will you attack the enemy vigorously so that we may attack them along with you?" So Az-Zubair attacked them, and they inflicted two wounds over his shoulder, and in between these two wounds there was an old scar he had received on the day of the battle of Badr When I was a child, I used to insert my fingers into those scars in play.  

أَنَّ أَصْحَابَ النَّبِيِّ ﷺ قَالُوا لِلزُّبَيْرِ يَوْمَ الْيَرْمُوكِ أَلاَ تَشُدُّ فَنَشُدَّ مَعَكَ فَحَمَلَ عَلَيْهِمْ فَضَرَبُوهُ ضَرْبَتَيْنِ عَلَى عَاتِقِهِ بَيْنَهُمَا ضَرْبَةٌ ضُرِبَهَا يَوْمَ بَدْرٍ قَالَ عُرْوَةُ فَكُنْتُ أُدْخِلُ أَصَابِعِي فِي تِلْكَ الضَّرَبَاتِ أَلْعَبُ وَأَنَا صَغِيرٌ