Hadith 667

نا مُحَمَّدُ بْنُ الْمُثَنَّى ، وَأَحْمَدُ بْنُ الْمِقْدَامِ ، قَالا : حَدَّثَنَا مُلازِمُ بْنُ عَمْرٍو ، حَدَّثَنِي جَدِّي عَبْدُ اللَّهِ بْنُ بَدْرٍ ، عَنْ عَبْدِ الرَّحْمَنِ بْنِ عَلِيٍّ ، عَنْ أَبِيهِ عَلِيِّ بْنِ شَيْبَانَ وَكَانَ أَحَدَ الْوَفْدِ ، قَالَ : صَلَّيْتُ خَلْفَ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ ، فَلَمَحَ بِمُؤَخِّرِ عَيْنِهِ إِلَى رَجُلٍ لا يُقِيمُ صُلْبَهُ فِي الرُّكُوعِ وَالسُّجُودِ ، فَلَمَّا قَضَى نَبِيُّ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ الصَّلاةَ ، قَالَ : " يَا مَعْشَرَ الْمُسْلِمِينَ ، إِنَّهُ لا صَلاةَ لِمَنْ لا يُقِيمُ صُلْبَهُ فِي الرُّكُوعِ وَالسُّجُودِ " . هَذَا حَدِيثُ أَحْمَدَ بْنِ الْمِقْدَامِ
Hazrat Ali bin Shiban, who was a member of the (delegation that came to serve the Prophet), says that I offered prayer behind the Messenger of Allah (peace be upon him). The Prophet (peace be upon him) glanced sideways and saw a man who was not straightening his back during bowing (ruku) and prostration (sajdah). Then, when the Prophet (peace be upon him) completed the prayer, he said: "O assembly of Muslims, indeed the prayer of the one who does not straighten his back during bowing and prostration is not valid." This is the hadith of Ahmad bin Al-Muqaddam.
Hadith Reference صحيح ابن خزيمه / جماع أبواب الأذان والإقامة / 667