عَنْ عَبْدِ الرَّحْمَنِ بْنِ أَبِي لَيْلَى عَنْ أُبَيِّ بْنِ كَعْبٍ رَضِيَ اللَّهُ عَنْهُ أَوْ عَنْ رَجُلٍ مِنَ الْأَنْصَارِ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ مَنْ قَرَأَ بِـ قُلْ هُوَ اللَّهُ أَحَدٌ [الإخلاص: 1] فَكَأَنَّمَا قَرَأَ بِثُلُثِ الْقُرْآنِ
It is narrated from Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him) or from some Ansari companion that the Noble Prophet (peace and blessings be upon him and his family) said: Whoever recites Surah {قُلْ ھُوَ اللّٰہُ اَحَدٌ }, it is as if he has recited one third of the Holy Qur'an.