ENOfficial
It was narrated that from ‘Amr bin Shu’aib, from his father, from his grandfather, that the Messenger of Allah (ﷺ) said: “Every prayer in which Fatihatil-Kitab (the Opening of the Book) is not recited, it is deficient, it is deficient.”
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا الْوَلِيدُ بْنُ عَمْرِو بْنِ السُّكَيْنِ، حَدَّثَنَا يُوسُفُ بْنُ يَعْقُوبَ السَّلْعِيُّ، حَدَّثَنَا حُسَيْنٌ الْمُعَلِّمُ، عَنْ عَمْرِو بْنِ شُعَيْبٍ، عَنْ أَبِيهِ، عَنْ جَدِّهِ، أَنَّ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ قَالَ " كُلُّ صَلاَةٍ لاَ يُقْرَأُ فِيهَا بِفَاتِحَةِ الْكِتَابِ فَهِيَ خِدَاجٌ فَهِيَ خِدَاجٌ " .
sunnah.com