(60) باب وَقْتِ رَكْعَتَىِ الْفَجْرِ وَذِكْرِ الاِخْتِلاَفِ عَلَى نَافِعٍ
It was narrated from Ibn 'Umar that Hafsah, the Mother of the Believers, :
Told him that when the Muaddhin fell silent, Allah's Messenger (ﷺ) would pray two brief rak'ahs. (ES)
Reference (ES): Sunan an-Nasa'i 1772 (ES)
In-book reference (ES): Book 20, Hadith 175 (ES)
English translation (ES): Vol. 2, Book 20, Hadith 1773 (ES)