Musnad Abu Ya'la al-Mawsili 2:103

Abu Khaythama narrated to us, Waki' narrated to us, Kahmas narrated to us, from 'Abdullah ibn Buraydah, from Yahya ibn Ya'mar, from Ibn 'Umar, from 'Umar, that Jibril came to the Prophet, peace and blessings of Allah be upon him, and said: "What is faith?" He said: "To believe in Allah, His angels, His books, His messengers, the Last Day, and to believe in the decree, its good and its evil." Jibril said: "You have spoken the truth." We were amazed at him; he asks him and then confirms him. The Prophet, peace and blessings of Allah be upon him, said: "That was Jibril; he came to you to teach you your religion."