(81) باب مَا جَاءَ فِيمَنْ لاَ يُقِيمُ صُلْبَهُ فِي الرُّكُوعِ وَالسُّجُودِ
Abu Mas'ud Al-Ansari [Al-Badri] narrated that :
Allah's Messenger said: "The Salat is not acceptable if a man is not at rest - meaning his back - while bowing and prostrating." (TR)
Reference (TR): Jami` at-Tirmidhi 265 (TR)
In-book reference (TR): Book 2, Hadith 117 (TR)
English translation (TR): Vol. 1, Book 2, Hadith 265 (TR)