Al-Bara' (b. 'Azib), and he was no liar (but a truthful Companion of the Holy Prophet), reported:
They used to say prayer behind the Messenger of Allah ( صلی اللہ علیہ وسلم ). I never saw anyone bending his back at the time when he (the Holy Prophet) raised his head, till the Messenger of Allah ( صلی اللہ علیہ وسلم ) placed his forehead on the ground. They then fell in prostration after him.