Sahih Muslim Book - 6, Hadith - 1885

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِى شَيْبَةَ حَدَّثَنَا عَبْدُ الأَعْلَى بْنُ عَبْدِ الأَعْلَى عَنِ الْجُرَيْرِىِّ عَنْ أَبِى السَّلِيلِ عَنْ عَبْدِ اللَّهِ بْنِ رَبَاحٍ الأَنْصَارِىِّ عَنْ أُبَىِّ بْنِ كَعْبٍ قَالَ قَالَ رَسُولُ اللَّهِ -صلى الله عليه وسلم- « يَا أَبَا الْمُنْذِرِ أَتَدْرِى أَىُّ آيَةٍ مِنْ كِتَابِ اللَّهِ مَعَكَ أَعْظَمُ ». قَالَ قُلْتُ اللَّهُ وَرَسُولُهُ أَعْلَمُ. قَالَ « يَا أَبَا الْمُنْذِرِ أَتَدْرِى أَىُّ آيَةٍ مِنْ كِتَابِ اللَّهِ مَعَكَ أَعْظَمُ ». قَالَ قُلْتُ اللَّهُ لاَ إِلَهَ إِلاَّ هُوَ الْحَىُّ الْقَيُّومُ. قَالَ فَضَرَبَ فِى صَدْرِى وَقَالَ « وَاللَّهِ لِيَهْنِكَ الْعِلْمُ أَبَا الْمُنْذِرِ ».

It was narrated that Ubayy bin Ka'b said: "The Messenger of Allah (s.a.w) said: 'O Abu Al-Mundhir, do you know which verse from the Book of Allah that you have learned is greatest?' I said: 'Allah and His Messenger know best.' He said: 'O Abu Al-Mundhir, do you know which verse from the Book of Allah that you have learned is greatest?' I said: "'Allahu! la ilaha illa Huwa (none has the right to be worshiped but He), Al-Hayyul-Qayyum (the Ever Living, the One Who sustains and protects all that exists...)."' He struck me on the chest and said: 'I congratulate you on your knowledge, O Abu Al-Mundhir.'"