Musnad Abu Ya'la al-Mawsili 110:258

Zuhayr narrated to us, Wahb ibn Jarir narrated to us, my father narrated to us, he said: I heard Ya’la ibn Hakim narrating from ‘Ikrimah, from Ibn ‘Abbas, that the Messenger of Allah (may Allah bless him and grant him peace) went out during his illness in which he died, with his head bound with a cloth. He sat upon the pulpit, praised Allah, and extolled Him. Then he said: "There is no one among the people who has been more generous to me with his self and his wealth than Ibn Abi Quhafa. If I were to take a close friend (khalil) from the people, I would have taken Abu Bakr, but the brotherhood of Islam is better. Block every small door (khawkha) in the mosque except the small door of Abu Bakr."