Sahih Muslim 395
Sahih Muslim · Book 4: The Book of Prayers · It Is Obligatory To Recite Al-Fatihah In Every Rak'ah; If A Person Cannot Recite Al-Fatihah Or Cannot Learn It, Then He Should Recite Whatever Else He Can Manage
Abu Huraira reported:
حَدَّثَنِي أَحْمَدُ بْنُ جَعْفَرٍ الْمَعْقِرِيُّ ، حَدَّثَنَا النَّضْرُ بْنُ مُحَمَّدٍ ، حَدَّثَنَا أَبُو أُوَيْسٍ ، أَخْبَرَنِي الْعَلاَءُ ، قَالَ سَمِعْتُ مِنْ أَبِي وَمِنْ أَبِي السَّائِبِ ، وَكَانَا، جَلِيسَىْ أَبِي هُرَيْرَةَ قَالاَ قَالَ أَبُو هُرَيْرَةَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ صَلَّى صَلاَةً لَمْ يَقْرَأْ فِيهَا بِفَاتِحَةِ الْكِتَابِ فَهْىَ خِدَاجٌ " . يَقُولُهَا ثَلاَثًا بِمِثْلِ حَدِيثِهِمْ .
The Messenger of Allah (ﷺ) said: He who said his prayer, but did not recite the opening chapter of al-Kitab, his prayer is incomplete. He repeated it thrice.