Musnad Abu Ya'la al-Mawsili 167:1

Dāwūd ibn Rashīd narrated to us, Muʿammar narrated to us, from Ḥajjāj, from al-Furāt Abū ʿAbd Allāh, from Saʿīd ibn Jubayr, who said: I was sitting with ʿAbd Allāh ibn ʿUtbah ibn Masʿūd, and Ibn al-Zubayr had appointed him over the judiciary of Kufa, when a letter from Ibn al-Zubayr came to him: "Peace be upon you. To proceed: You were asking me about the grandfather. Indeed, the Messenger of Allah (peace be upon him) said: 'If I were to take a close friend (khalīl) from this nation other than my Lord, I would have taken the son of Abū Quḥāfah, but he is my brother in religion and my companion in the cave.' And he made the grandfather a father, so the most worthy of what we should take is the statement of Abū Bakr."