Call to Prayers (Adhaan)

Bukhari :: Book 1 :: Volume 11 :: Hadith 643

Narrated Ja'far bin 'Amr bin Umaiya:

My father said, "I saw Allah's Apostle eating a piece of meat from the shoulder of a sheep and he was called for the prayer. He stood up, put down the knife and prayed but did not perform ablutilon.''