Musnad Abu Ya'la al-Mawsili 149:89

Abu Bakr narrated to us, Zayd ibn al-Hubab narrated to us, from Abdullah ibn al-Mu'ammal, Abdullah ibn Abi Mulaykah narrated to us, From Aisha, that the Messenger of Allah, peace and blessings of Allah be upon him, said: "Excellent is the condiment, vinegar."