Musannaf Ibn Abi Shayba 4:908

Abu Khalid al-Ahmar narrated to us, from Muhammad ibn ‘Ajlan, from al-Muttalib ibn Abi Wada’ah, from Sa’id ibn al-Musayyib, who said: A man came to the Prophet, may Allah bless him and grant him peace, and said: "I broke my fast on a day of Ramadan." The Prophet, may Allah bless him and grant him peace, said to him: "Give charity, seek forgiveness from Allah, and fast a day in its place."