Muwatta Imam Malik Book of Tahajjud, Hadith 30

Malik related to me from Yahya ibn Said that A'isha, the wife of the Prophet ﷺ said, "The Messenger of Allah ﷺ used to pray the two rakas of the dawn (fajr) so quickly that I would say to myself 'Has he recited the umm al-Qur'an or not?' "

وَحَدَّثَنِي مَالِكٌ، عَنْ يَحْيَى بْنِ سَعِيدٍ، أَنَّ عَائِشَةَ، زَوْجَ النَّبِيِّ ﷺ قَالَتْ إِنْ كَانَ رَسُولُ اللَّهِ ﷺ لَيُخَفِّفُ رَكْعَتَىِ الْفَجْرِ حَتَّى إِنِّي لأَقُولُ أَقَرَأَ بِأُمِّ الْقُرْآنِ أَمْ لاَ