Hadith 301:1
'Abd al-Samad and Surayj narrated to us, they said: Mulazim ibn 'Amr narrated to us, 'Abd Allah ibn Badr narrated to us, that 'Abd al-Rahman ibn 'Ali narrated to him, that his father 'Ali ibn Shayban narrated to him, that he went as a delegate to the Messenger of Allah (may Allah bless him and grant him peace). He said: We prayed behind the Prophet (may Allah bless him and grant him peace), and he glanced with the corner of his eye at a man who was not straightening his back in the bowing (ruku') and the prostration (sujud). When the Messenger of Allah (may Allah bless him and grant him peace) finished, he said: "O assembly of Muslims, there is no prayer for one who does not straighten his back in the bowing and the prostration." He said: And he saw a man praying behind the row, so he waited until the man finished, and the Messenger of Allah (may Allah bless him and grant him peace) said: "Restart your prayer; there is no prayer for a man alone behind the row." 'Abd al-Samad said: "Alone behind the row," so he said to him: "Restart your prayer, for there is no prayer for one alone behind the row."
حدثنا عبد الصمد، وسريج، قالا: حدثنا ملازم بن عمرو، حدثنا عبد الله بن بدر، أن عبد الرحمن بن علي حدثه، أن أباه علي بن شيبان حدثه، أنه خرج وافدا إلى رسول الله صلى الله عليه وسلم قال: فصلينا خلف النبي صلى الله عليه وسلم، فلمح بمؤخر عينه إلى رجل لا يقيم صلبه في الركوع والسجود، فلما انصرف رسول الله صلى الله عليه وسلم قال: " يا معشر المسلمين، إنه لا صلاة لمن لا يقيم صلبه في الركوع والسجود " قال: ورأى رجلا يصلي خلف الصف، فوقف حتى انصرف الرجل، فقال رسول الله صلى الله عليه وسلم: " استقبل صلاتك، لا صلاة لرجل فرد خلف الصف "، قال عبد الصمد: " فردا خلف الصف " فقال له " استقبل صلاتك، فلا صلاة لفرد خلف الصف "