أَخْبَرَنَا مُحَمَّدُ بْنُ سَلَمَةَ، قَالَ أَنْبَأَنَا ابْنُ الْقَاسِمِ، عَنْ مَالِكٍ، قَالَ حَدَّثَنِي نَافِعٌ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّ حَفْصَةَ أُمَّ الْمُؤْمِنِينَ، أَخْبَرَتْهُ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ إِذَا سَكَتَ الْمُؤَذِّنُ مِنَ الأَذَانِ لِصَلاَةِ الصُّبْحِ وَبَدَا الصُّبْحُ صَلَّى رَكْعَتَيْنِ خَفِيفَتَيْنِ قَبْلَ أَنْ تُقَامَ الصَّلاَةُ .
It was narrated from 'Abdullah bin Umar that Hafsah, the Mother of the Believers, told him: that when the Muaddhin fell silent following the call to Subh prayer and dawn had broken, he would pray two brief rak'ahs before getting up to pray. Translation Not Available
Book Ref: Sunan An Nisai Book 20 Hadith 1773
Web Ref: Sunan An Nisai Vol 2 Book 20 Hadith 1774