The Book of Prayers (Kitab Al-Salat)
Muslim :: Book 4 : Hadith 1991
'Abd al-Rahman b. Samura said: During the lifetime of Allah's Messenger (may peace be upon him) I was shooting my arrows in Medina, when an eclipse of the sun took place. I, therefore, threw them away and said, I must see how the Messenger of Allah (may peace be upon him) acts in a solar eclipse today. When I came to him, he had been supplicating with his hands, raised, pronouncing Allah-o-Akbar, praising Him, acknowledging that He is One God till the eclipse was over, then he recited two surahs and prayed two rak'ahs.