The Prophet ﷺ was not more diligent in observing any voluntary prayer than he was with the two rakahs before Fajr.
لم يكن النبي ﷺ على شيء من النوافل أشد منه تعاهدا على ركعتي الفجر.
Bukhari narrated it in tahajjud (1169), and Muslim in the Travelers (94/724), both through the route of Yahya bin Saeed, from Ibn Jurayj, who said, Atta told me, from Ubayd bin Umayr, from Ayesha, and mentioned it. In the version of Hafs, from Ibn Jurayj, with the same wording, she said, "I never saw the Messenger of Allah ﷺ hasten to any voluntary prayer more than he hastened to the two units before Fajr." Muslim narrated it from Ibn Numayr, from him.Ibn Khuzayma narrated it (1108) from Abdullah bin Saeed Ashaj, who said, Hafs, meaning Ibn Ghiyath, narrated to us with the same wording, and he added in it, "nor to a spoil of war."