Sahih Bukhari Volume 6, Book 60, Hadith Number 186.

Narrated By Ibn Abi Mulaika : When there happened the disagreement between Ibn Az-Zubair and Ibn ‘Abbas, I said (to the latter), “(Why don’t you take the oath of allegiance to him as) his father is Az-Zubair, and his mother is Asma,’ and his aunt is ‘Aisha, and his maternal grandfather is Abu Bakr, and his grandmother is Safiya?”