Musnad Abu Ya'la al-Mawsili 1:48

Al-Qawariri narrated to us, Ghundar narrated to us, Ma'mar narrated to us, from Ibn Shihab, from 'Urwah, from 'Aishah: That Abu Bakr entered upon her while there were two young girls with her beating a tambourine. Abu Bakr rebuked them. The Prophet, peace and blessings of Allah be upon him, said to him: "Leave them, for every people have an Eid (festival)."