´It was narrated from Mahmud bin Labid, from some men among his people who were of the Ansar, that the Messenger of Allah (ﷺ) said:` "The more you delay Fajr, the greater the reward."
Hadith Referenceسنن نسائي / كتاب المواقيت / 550
Hadith Gradingالألبانی:صحيح الإسناد | زبیر علی زئی:إسناده صحيح