Musnad Abu Ya'la al-Mawsili 1:46

Al-Qawariri narrated to us, Marhum bin 'Abd al-'Aziz narrated to us, Abu 'Imran al-Jawni narrated to us, from Yazid bin Babnus, from 'Aishah: That Abu Bakr entered upon the Prophet, may Allah bless him and grant him peace, after his death. He placed his mouth between his eyes, placed his hands on his temples, and said: "O my Prophet! O my intimate friend! O my chosen one!"