The Prophet ﷺ used to make the two units of prayer before the dawn prayer so brief that I would wonder whether he had even recited the opening chapter of the Quran in them.
حدثنا أحمد بن أبي شعيب الحراني حدثنا زهير بن معاوية حدثنا يحيى بن سعيد عن محمد بن عبد الرحمن عن عمرة
كان النبي ﷺ يخفف الركعتين قبل صلاة الفجر حتى إني لأقول هل قرأ فيهما بأم القرآن
Bukhari related it in the Book of Tahajjud, chapter on what is recited in the two rakahs of Fajr, hadith no. 1171, from the hadith of Zuhayr bin Muawiya. Muslim related it in the Book of the Prayer of Travelers, chapter on the recommendation of the two sunnah rakahs of Fajr and encouragement to perform them, hadith no. 92/724, from the hadith of Yahya bin Saeed Ansari, through the same chain.