Narrated Ibn Abi Mulaika:

There was a disagreement between them (i.e. Ibn `Abbas and Ibn Az-Zubair) so I went to Ibn `Abbas in the morning and said (to him), "Do you want to fight against Ibn Zubair and thus make lawful what Allah has made unlawful (i.e. fighting in Meccas?" Ibn `Abbas said, "Allah forbid! Allah ordained that Ibn Zubair and Bani Umaiya would permit (fighting in Mecca), but by Allah, I will never regard it as permissible." Ibn `Abbas added. "The people asked me to take the oath of allegiance to Ibn AzZubair. I said, 'He is really entitled to assume authority for his father, Az-Zubair was the helper of the Prophet, his (maternal) grandfather, Abu Bakr was (the Prophet's) companion in the cave, his mother, Asma' was 'Dhatun-Nitaq', his aunt, `Aisha was the mother of the Believers, his paternal aunt, Khadija was the wife of the Prophet (ﷺ) , and the paternal aunt of the Prophet (ﷺ) was his grandmother. He himself is pious and chaste in Islam, well versed in the Knowledge of the Qur'an. By Allah! (Really, I left my relatives, Bani Umaiya for his sake though) they are my close relatives, and if they should be my rulers, they are equally apt to be so and are descended from a noble family.

حَدَّثَنِي عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ، قَالَ حَدَّثَنِي يَحْيَى بْنُ مَعِينٍ، حَدَّثَنَا حَجَّاجٌ، قَالَ ابْنُ جُرَيْجٍ قَالَ ابْنُ أَبِي مُلَيْكَةَ وَكَانَ بَيْنَهُمَا شَىْءٌ فَغَدَوْتُ عَلَى ابْنِ عَبَّاسٍ فَقُلْتُ أَتُرِيدُ أَنْ تُقَاتِلَ ابْنَ الزُّبَيْرِ، فَتُحِلُّ حَرَمَ اللَّهِ‏.‏ فَقَالَ مَعَاذَ اللَّهِ، إِنَّ اللَّهَ كَتَبَ ابْنَ الزُّبَيْرِ وَبَنِي أُمَيَّةَ مُحِلِّينَ، وَإِنِّي وَاللَّهِ لاَ أُحِلُّهُ أَبَدًا‏.‏ قَالَ قَالَ النَّاسُ بَايِعْ لاِبْنِ الزُّبَيْرِ‏.‏ فَقُلْتُ وَأَيْنَ بِهَذَا الأَمْرِ عَنْهُ أَمَّا أَبُوهُ فَحَوَارِيُّ النَّبِيِّ صلى الله عليه وسلم، يُرِيدُ الزُّبَيْرَ، وَأَمَّا جَدُّهُ فَصَاحِبُ الْغَارِ، يُرِيدُ أَبَا بَكْرٍ، وَأُمُّهُ فَذَاتُ النِّطَاقِ، يُرِيدُ أَسْمَاءَ، وَأَمَّا خَالَتُهُ فَأُمُّ الْمُؤْمِنِينَ، يُرِيدُ عَائِشَةَ، وَأَمَّا عَمَّتُهُ فَزَوْجُ النَّبِيِّ صلى الله عليه وسلم، يُرِيدُ خَدِيجَةَ، وَأَمَّا عَمَّةُ النَّبِيِّ صلى الله عليه وسلم فَجَدَّتُهُ، يُرِيدُ صَفِيَّةَ، ثُمَّ عَفِيفٌ فِي الإِسْلاَمِ، قَارِئٌ لِلْقُرْآنِ‏.‏ وَاللَّهِ إِنْ وَصَلُونِي وَصَلُونِي مِنْ قَرِيبٍ، وَإِنْ رَبُّونِي رَبَّنِي أَكْفَاءٌ كِرَامٌ، فَآثَرَ التُّوَيْتَاتِ وَالأُسَامَاتِ وَالْحُمَيْدَاتِ، يُرِيدُ أَبْطُنًا مِنْ بَنِي أَسَدٍ بَنِي تُوَيْتٍ وَبَنِي أُسَامَةَ وَبَنِي أَسَدٍ، إِنَّ ابْنَ أَبِي الْعَاصِ بَرَزَ يَمْشِي الْقُدَمِيَّةَ، يَعْنِي عَبْدَ الْمَلِكِ بْنَ مَرْوَانَ، وَإِنَّهُ لَوَّى ذَنَبَهُ، يَعْنِي ابْنَ الزُّبَيْرِ‏.‏
USC-MSA web (English) reference : Vol. 6, Book 60, Hadith 187
Arabic reference : Book 65, Hadith 4665