Musnad Ahmad 30:1241

Abu Asim narrated to us, Al-Awza'i narrated to us, Qurrah ibn Abd al-Rahman narrated to us, from Ibn Shihab, from Abu Salamah, from Abu Hurairah, who said: The Messenger of Allah, peace and blessings of Allah be upon him, said: "Allah, the Mighty and Majestic, says: 'Indeed, the most beloved of My servants to Me are those who are the swiftest in breaking their fast.'"