Musnad Ahmad 1153:1694

Waki’ and ‘Abd al-Rahman narrated to us, they said: Sufyan narrated to us, from ‘Asim ibn ‘Ubayd Allah, from al-Qasim ibn Muhammad, from ‘Aisha, she said: The Messenger of Allah (peace and blessings of Allah be upon him) kissed—‘Abd al-Rahman said: I saw the Messenger of Allah (peace and blessings of Allah be upon him) kissing—and Waki’ said: She said: "The Messenger of Allah (peace and blessings of Allah be upon him) kissed ‘Uthman ibn Maz’un while he was dead." She said: "So I saw his tears flowing upon his cheeks," meaning ‘Uthman. ‘Abd al-Rahman said: "And his eyes were shedding tears," or he said: "And he was weeping."