Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
bayhaqi:2571 – Abū al-Qāsim Zayd b. Jaʿfar b. Muḥammad b. ʿAlī al-ʿAlawī And ʾAbū al-Qāsim ʿAbd al-Wāḥid b. Muḥammad b. al-Bukhārī al-Muqriʾ Bi-al-Kūfah from Aṣl Samāʿihimā > Abū Jaʿfar Muḥammad b. ʿAlī b. Duḥaym al-Qāḍī > Ibrāhīm b. Isḥāq > Qabīṣah > Sufyān > al-Aʿmash > ʿUmārah b. ʿUmayr > Abū Maʿmar > Abū Masʿūd

[Machine] The Messenger of Allah ﷺ said: "The prayer of a person who does not establish the straightness of his back during the bowing and prostration does not count." This is a sound chain of narration and it is also confirmed.  

البيهقي:٢٥٧١ – وَأَخْبَرَنَا أَبُو الْقَاسِمِ زَيْدُ بْنُ جَعْفَرِ بْنِ مُحَمَّدِ بْنِ عَلِيٍّ الْعَلَوِيُّ وَأَبُو الْقَاسِمِ عَبْدُ الْوَاحِدِ بْنُ مُحَمَّدِ بْنِ الْبُخَارِيِّ الْمُقْرِئُ بِالْكُوفَةِ مِنْ أَصْلِ سَمَاعِهِمَا قَالَا ثنا أَبُو جَعْفَرٍ مُحَمَّدُ بْنُ عَلِيِّ بْنِ دُحَيْمٍ الْقَاضِي ثنا إِبْرَاهِيمُ بْنُ إِسْحَاقَ ثنا قَبِيصَةُ عَنْ سُفْيَانَ عَنِ الْأَعْمَشِ عَنْ عُمَارَةَ بْنِ عُمَيْرٍ عَنْ أَبِي مَعْمَرٍ عَنْ أَبِي مَسْعُودٍ ؓ قَالَ

قَالَ رَسُولُ اللهِ ﷺ لَا يُجْزِي صَلَاةُ رَجُلٍ لَا يُقِيمُ فِيهَا صُلْبَهُ فِي الرُّكُوعِ وَالسُّجُودِ هَذَا إِسْنَادٌ صَحِيحٌ وَكَذَلِكَ  

رَوَاهُ عَامَّةُ أَصْحَابِ الْأَعْمَشِ عَنِ الْأَعْمَشِ