It was narrated that Anas said:"The Messenger of Allah (ﷺ) prayed Fajr on the day of Khaibar during the time it was still dark, when he was near the enemy. Then he attacked them and said: 'Allahu Akbar! Khaibar is destroyed!' Twice. 'Then, when it descends in their courtyard, evil will be the morning for those who had been warned!'" [1] [1] As-Saffat 37:
Hadith No. 547
Sunan an Nasai
Gradings:
Abu Ghuddah:
Sahih
Al-Albani:
Sahih
Zubair Ali Zai:
Sahih Bukhari