(60) باب وَقْتِ رَكْعَتَىِ الْفَجْرِ وَذِكْرِ الاِخْتِلاَفِ عَلَى نَافِعٍ
It was narrated from Ibn Umar, from Hafsah, that:
When the call to Subh prayer was given, the Messenger of Allah (ﷺ) would pray two brief rak'ahs before going to pray. (ID)
Reference (ID): Sunan an-Nasa'i 1777 (ID)
In-book reference (ID): Book 20, Hadith 180 (ID)
English translation (ID): Vol. 2, Book 20, Hadith 1778 (ID)