Musnad Ahmad 284:9

Mu'ammar ibn Sulayman al-Raqqi narrated to us, he said: al-Hajjaj narrated to us, from Furat ibn 'Abd Allah—and he is Furat al-Qazzaz—from Sa'id ibn Jubayr, he said: I was sitting with 'Abd Allah ibn 'Utbah ibn Mas'ud, and Ibn al-Zubayr had appointed him as a judge, when a letter from Ibn al-Zubayr came to him: "Peace be upon you. To proceed: You wrote asking me about the grandfather? Indeed, the Messenger of Allah (peace and blessings of Allah be upon him) said: 'If I were to take a *khalil* (intimate friend) from this nation other than my Lord, the Mighty and Majestic, I would have taken the son of Abu Quhafah, but he is my brother in religion and my companion in the cave.'" He made the grandfather a father, and the most rightful thing we have adopted is the statement of Abu Bakr al-Siddiq (may Allah be pleased with him).