Musnad Ahmad 1153:1914

Ibn Numayr narrated to us, al-A‘mash narrated to us, from Ibrahim, from al-Aswad, from ‘A’ishah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) would engage in physical intimacy (mubasharah) while he was fasting, because he was the most capable among you of controlling his desire.