(and he was not a liar) We used to pray behind the Prophet and when he...

Hadith 1:775

Narrated Al-Bara' bin 'Azib:

(and he was not a liar) We used to pray behind the Prophet and when he said, "Sami' a-l-lahu Liman hamida", none of us would bend his back (to go for prostration) till the Prophet had placed his, forehead on the ground.