Hafsa reported that when it was dawn, the Messenger of Allah ﷺ did not observe (any other prayers) but two short rak'ahs. (Using translation from Muslim 723c)
كَانَ رَسُولُ اللهِ ﷺ «إِذَا طَلَعَ الْفَجْرُ لَا يُصَلِّي إِلَّا رَكْعَتَيْنِ خَفِيفَتَيْنِ»