Musnad Ahmad 1153:1948

Hisham ibn Sa'id narrated to us, he said: Muhammad ibn Dinar informed us, from Sa'd ibn Aws, from Musda' Abu Yahya al-Ansari, from Aisha, she said: The Messenger of Allah (peace and blessings of Allah be upon him) used to kiss her while he was fasting, and he would suck her tongue.