Musnad Abu Ya'la al-Mawsili 147:36

Muhammad ibn Abd Allah ibn Numayr narrated to us, Abu Khalid narrated to us, from al-Hasan ibn Ubayd Allah, from Thalabah, from Anas, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "How wondrous is the affair of the believer; no decree is decreed for him except that it is good for him."