It was narrated from Ibn 'Umar that Hafsah said:
"When the dawn appears, the Messenger of Allah (ﷺ) would only pray two short Rak'ahs." (JA)
English reference (JA): Vol. 1, Book 6, Hadith 584 (JA)
Arabic reference (JA): Book 6, Hadith 590 (JA)