Musnad Ahmad 30:123

Al-Walid narrated to us, Al-Awza'i narrated to us, Qurrah narrated to me, from Al-Zuhri, from Abu Salamah, from Abu Hurairah, from the Prophet, peace and blessings of Allah be upon him, who said: "Allah, the Mighty and Majestic, says: 'Indeed, the most beloved of My servants to Me are those who are swiftest in breaking their fast.'"