Sunan An-Nasa'i - سنن النسائي
12. The Book of The At-Tatbiq (Clasping One's Hands Together) - كتاب التطبيق
27) Chapter: The Qunut during the Subh prayer
It was narrated that Ibn Sirin said:
"Some of those who prayed the Subh prayer with the Messenger of Allah (ﷺ) narrated to me that when he said: Sami'Allahu liman hamidah (Allah hears those who praise Him)' in the second rak'ah, he stood for a while."
27) باب الْقُنُوتِ فِي صَلاَةِ الصُّبْحِ
أَخْبَرَنَا إِسْمَاعِيلُ بْنُ مَسْعُودٍ، قَالَ حَدَّثَنَا بِشْرُ بْنُ الْمُفَضَّلِ، عَنْ يُونُسَ، عَنِ ابْنِ سِيرِينَ، قَالَ حَدَّثَنِي بَعْضُ، مَنْ صَلَّى مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم صَلاَةَ الصُّبْحِ فَلَمَّا قَالَ . فِي الرَّكْعَةِ الثَّانِيَةِ قَامَ هُنَيْهَةً . " سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ "