قَوْلُهُ تَعَالَى: {وَلَقَدْ آتَيْنَاكَ سَبْعًا مِنَ الْمَثَانِي} [الحجر: 87]
I prayed ant then I came to him. He asked: What prevented you from answering me ? He replied: I was praying. He said: Has not Allah said: "O you who believe, respond to Allah and the Apostle when he calls you to that which gives you life ? (8:24) Let me teach you the greatest surah from the Qur'an or in the Qur'an (the narrator Khalid doubted) before I leave the mosque. I said: (I shall memorize) your saying. He said: It is: "Praise be to Allah, the Lord of the Universe" which is the seven oft-repeated verses, and the mighty Qur'an. (Using translation from Abū Dāʾūd 1458)
مَرَّ بِي رَسُولُ اللهِ ﷺ وَأَنَا فِي الْمَسْجِدِ فَدَعَانِي فَلَمْ آتِهِ قَالَ «مَا مَنَعَكَ أَنْ تَأْتِيَنِي؟» قُلْتُ إِنِّي كُنْتُ أُصَلِّي قَالَ أَلَمْ يَقُلِ اللهُ ﷻ {يَا أَيُّهَا الَّذِينَ آمَنُوا اسْتَجِيبُوا لِلَّهِ وَلِلرَّسُولِ إِذَا دَعَاكُمْ لِمَا يُحْيِيكُمْ} [الأنفال 24] قَالَ «أَلَا أُعَلِّمُكَ أَفْضَلَ سُورَةٍ فِي الْقُرْآنِ قَبْلَ أَنْ أَخْرُجَ؟» فَلَمَّا ذَهَبَ يَخْرُجُ ذَكَرْتُ ذَلِكَ لَهُ قَالَ فَقَالَ الْحَمْدُ لِلَّهِ رَبِّ الْعَالَمِينَ هِيَ السَّبْعُ الْمَثَانِي وَالْقُرْآنُ الْعَظِيمُ الَّذِي أُوتِيتُهُ