Sahih al-Bukhari, Volume 2, Book 16, Hadith 118 (USC-MSA) ⓘ

Narrated Anas: The Qunut used to be recited in the Maghrib and the Fajr prayers.

حَدَّثَنَا مُسَدَّدٌ، قَالَ حَدَّثَنَا إِسْمَاعِيلُ، قَالَ حَدَّثَنَا خَالِدٌ، عَنْ أَبِي قِلاَبَةَ، عَنْ أَنَسٍ، قَالَ كَانَ الْقُنُوتُ فِي الْمَغْرِبِ وَالْفَجْرِ‏.‏

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also referenced under: Book 14, Hadith 15 (In-Book) & Hadith 1004 (DarusSalam)