Musnad Abu Ya'la al-Mawsili 150:192

Muhammad ibn Qudamah narrated to us, he said: I heard Sufyan saying: I said to Abd al-Rahman ibn al-Qasim: "Did you hear your father reporting from Aisha that the Prophet, peace and blessings of Allah be upon him, used to kiss while he was fasting?" He said: Then he remained silent regarding me for a while, then he said to me: "Yes," as if he considered me too young.