'A'isha reported that the Apostle (ﷺ) was not so much particular about observing supererogatory rak'ahs as in case of the two rak'ahs of the dawn prayer.
Sahih Muslim Book 6, Hadith 116
← Previous Hadith When it was dawn, the Messenger of Allah (ﷺ) observed two rak'ahs, and I would say: Does he recite only the opening chapter of the Qur'an in it?

Sahih Muslim Book 6, Hadith 115 Next Hadith → I have never seen the Messenger of Allah (ﷺ) hastening as much in observing supererogatory as two rak'ahs before the (Fard) of the dawn prayer.

Sahih Muslim Book 6, Hadith 117