Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) said that the Prophet (peace and blessings be upon him) said: "Allah, the Lord of Might, has added one prayer to your prayers. This prayer is better for you than red camels. Listen! It is the two rak'ahs before the Fajr prayer."
Al-Abbas bin al-Walid said: Yahya bin Ma'in said to me: This hadith is gharib (singular) from the narration of Mu'awiyah bin Sallam. Mu'awiyah bin Sallam is the hadith scholar of the people of Sham and he is saduq (truthful) in hadith; whoever does not write down his hadith, both its connected and its broken narrations, is not a man of hadith.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4463