When the call to Subh prayer was given, the Messenger of Allah (ﷺ) would pray two brief rak'ahs before going to pray.
Sunan an-Nasa'i Book 20, Hadith 180
← Previous Hadith "When dawn came, the Messenger of Allah (ﷺ) would not pray anything but two brief rak'ahs."

Sunan an-Nasa'i Book 20, Hadith 179 Next Hadith → "Hafsah told me that the Messenger of Allah (ﷺ) used to pray two brief rak'ahs before Fajr, and that was after dawn had broken."

Sunan an-Nasa'i Book 20, Hadith 181