“I heard Wabisah bin Ma’bad saying: ‘I saw the Messenger of Allah ﷺ performing prayer, and when he bowed he made his back so straight that if water were poured on it, it would have stayed there.’”
سَمِعْتُ وَابِصَةَ بْنَ مَعْبَدٍ يَقُولُ رَأَيْتُ رَسُولَ اللَّهِ ﷺ يُصَلِّي فَكَانَ إِذَا رَكَعَ سَوَّى ظَهْرَهُ حَتَّى لَوْ صُبَّ عَلَيْهِ الْمَاءُ لاَسْتَقَرَّ