Narrated Ubadah ibn as-Samit: We were behind the Messenger of Allah (ﷺ) at the dawn prayer, and he recited (the passage), but the recitation became difficult for him. Then when he finished, he said: Perhaps you recite behind your imam? We replied: Yes, it is so, Messenger of Allah. He said: Do not do so except when it is Fatihat al-Kitab, for he who does not recite it is not credited with having prayed.
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مُحَمَّدٍ النُّفَيْلِيُّ، حَدَّثَنَا مُحَمَّدُ بْنُ سَلَمَةَ، عَنْ مُحَمَّدِ بْنِ إِسْحَاقَ، عَنْ مَكْحُولٍ، عَنْ مَحْمُودِ بْنِ الرَّبِيعِ، عَنْ عُبَادَةَ بْنِ الصَّامِتِ، قَالَ كُنَّا خَلْفَ رَسُولِ اللَّهِ صلى الله عليه وسلم فِي صَلاَةِ الْفَجْرِ فَقَرَأَ رَسُولُ اللَّهِ صلى الله عليه وسلم فَثَقُلَتْ عَلَيْهِ الْقِرَاءَةُ فَلَمَّا فَرَغَ قَالَ " لَعَلَّكُمْ تَقْرَءُونَ خَلْفَ إِمَامِكُمْ " . قُلْنَا نَعَمْ هَذَا يَا رَسُولَ اللَّهِ . قَالَ " لاَ تَفْعَلُوا إِلاَّ بِفَاتِحَةِ الْكِتَابِ فَإِنَّهُ لاَ صَلاَةَ لِمَنْ لَمْ يَقْرَأْ بِهَا " .
sunnah.com