It is narrated from Sayyiduna Usamah bin Umayr (may Allah be pleased with him) that he prayed the two (sunnah) rak'ahs of Fajr with the Prophet (peace and blessings be upon him); he was praying standing close to him. He (peace and blessings be upon him) prayed two light rak'ahs, and he heard him saying three times: "O Allah, Lord of Jibril, Mika'il, Israfil and Muhammad (peace and blessings be upon him)! I seek refuge in You from the Fire."
Hadith Referenceالمعجم الكبير للطبراني / باب الألف / 517