(60) باب وَقْتِ رَكْعَتَىِ الْفَجْرِ وَذِكْرِ الاِخْتِلاَفِ عَلَى نَافِعٍ
It was narrated from Ibn 'Umar that Hafsah told him:
"When he was called to Subh prayer, the Messenger of Allah (ﷺ) would do two prostrations before Subh prayer." (DE)
Reference (DE): Sunan an-Nasa'i 1771 (DE)
In-book reference (DE): Book 20, Hadith 174 (DE)
English translation (DE): Vol. 2, Book 20, Hadith 1772 (DE)