Hafsa reported,

When dawn broke, the Messenger of Allah ﷺ would pray nothing but two brief units of prayer.

Muslim 1679

Sahih

و حدثناه إسحق بن إبراهيم أخبرنا النضر حدثنا شعبة بهذا الإسناد مثله

مسلم 1679صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Muslim
Book
Travelers' prayer and its shortening
Chapter
Recommendation of the two Fajr sunnah rakahs, encouragement to perform them, making them light, being consistent with them, and what is recommended to recite in them
Numbering
Darussalam 1679
Muslim 1679