Narrated Al-Bara' bin `Azib: (He was not a liar) We used to pray behind the Prophet and when he said, "Sami`a l-lahu liman hamidah", none of us would bend his back (to go for prostration) till the Prophet had placed his, forehead on the ground.
Hadith ReferenceSahih Bukhari / The Book of Adhan (Sufa-tus-Salat) / Hadith: 811
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة