If I add nothing to the (recitation) of the Umm al Qur'an (Surat al-Fatiha), would it make the prayer incomplete? He (AbuHuraira) said: If you add to that (if you recite some of verses of the Qur'an along with Surat at-Fatiha) that is better for you. But if you are contented with it (Surat al-Fatiha) only, it is sufficient for you. (Using translation from Muslim 396b)
قَالَ أَبُو هُرَيْرَةَ ؓ فِي كُلِّ صَلَاةٍ قِرَاءَةٌ فَمَا أَسْمَعَنَا رَسُولُ اللهِ ﷺ أَسْمَعْنَاكُمْ وَمَا أَخْفَى أَخْفَيْنَاهُ مِنْكُمْ فَقَالَ رَجُلٌ أَرَأَيْتَ إِنْ لَمْ أَزِدْ عَلَى أُمِّ الْقُرْآنِ؟ قَالَ إِنْ زِدْتَ عَلَيْهَا فَهُوَ خَيْرٌ وَإِنِ انْتَهَيْتَ عَلَيْهَا أَجْزَأَتْ عَنْكَ