Musnad Ahmad 1153:2171

Hammad ibn Khalid al-Khayyat narrated to us, he said: Abu Bakr al-Nahshali and Abu al-Mundhir narrated to us, they said: Abu Bakr narrated to me, from Ziyad ibn 'Alaqah, from 'Amr ibn Maymun, from 'Aishah: "That the Prophet, peace and blessings of Allah be upon him, used to kiss while he was fasting." Abu al-Mundhir said: "In Ramadan."