‏الصلاة : Hadeeth No:1549 Mu'adha asked 'A'isha (Allaah be pleased with her) how many rak'ahs Allaah's Messenger (sallAllaahu alayhi wa sallam) prayed at the forenoon prayer. She replied: Four rak'ahs, but sometimes more as he pleased....

‏الصلاة : Hadeeth No:1631 Zaid b. Arqam reported that the Messenger of Allaah (sallAllaahu alayhi wa sallam) went out to the people of Quba' and saw them observing prayer; upon this he said: The prayer of the penitent should be observed when the young weaned camels feel heat of the sun....