Musnad Ahmad 284:22

Yahya ibn Sa'id narrated to us, from Ibn Jurayj, from Ibn Abi Mulaykah, from Ibn al-Zubayr, who said: The one to whom the Messenger of Allah (peace and blessings of Allah be upon him) said, "If I were to take a *khalil* (intimate friend) other than Allah until I meet Him, I would have taken Abu Bakr," made the grandfather [equal to] the father.