Yahya related to me from Malik from Ibn Shihab from Said ibn al-Musayyab that the Messenger of Allah, may Allah bless him and granthim peace, travelled by night on the way back from Khaybar.Towards theend of the night he stopped for a rest and told Bilal to stay awake tokeep watch for the subh prayer. The Messenger of Allah, may Allahbless him and grant him peace, and his companions slept. Bilal stayedon guard as long as was decreed for him and then he leant against hisriding camel facing the direction of the dawn and sleep overcame himand neither he nor the Messenger of Allah nor any of the party woke upuntil the sun's rays had struck them. The Messenger of Allah, mayAllah bless him and grant him peace, was alarmed. Bilal excusedhimself, saying, "Messenger of Allah! The One who took your self wasthe One who took myself. "The Messenger of Allah, may Allah bless himand grant him peace, ordered the party to move on and so they rousedthei r mounts and rode on a short distance. The Messenger of Allah,may Allah bless him and grant him peace, ordered Bilal to give theiqama and then led them in the subh prayer. When he had finished hesaid, "Anyone who forgets a prayer should pray it when he remembers.Allah theBlessed and Exalted says in His book, 'Establish the prayerto remember Me.'"
Arabic/English book reference: Book 1, Hadith 25