Sunan an-Nasa'i, Volume 2, Book 14, Hadith 1412 (DarusSalam)

It was narrated from Muhammad bin 'Abdur-Rahman that: The daughter of Harithah bin An-Nu'man said: "I memorized 'Qaf. By the Glorious Qur'an.'" From the mouth of the Messenger of Allah when he was on the minbar on Friday."

أَخْبَرَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، قَالَ حَدَّثَنَا هَارُونُ بْنُ إِسْمَاعِيلَ، قَالَ حَدَّثَنَا عَلِيٌّ، - وَهُوَ ابْنُ الْمُبَارَكِ - عَنْ يَحْيَى، عَنْ مُحَمَّدِ بْنِ عَبْدِ الرَّحْمَنِ، عَنِ ابْنَةِ حَارِثَةَ بْنِ النُّعْمَانِ، قَالَتْ حَفِظْتُ ‏{‏ ق وَالْقُرْآنِ الْمَجِيدِ ‏}‏ مِنْ فِي رَسُولِ اللَّهِ صلى الله عليه وسلم وَهُوَ عَلَى الْمِنْبَرِ يَوْمَ الْجُمُعَةِ ‏.‏

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also referenced under: Book 14, Hadith 1422 (In-Book)