Sahih al-Bukhari 798
Book 10: Call to Prayers (Adhaan) · Narrated by Anas
Arabic
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ أَبِي الأَسْوَدِ، قَالَ حَدَّثَنَا إِسْمَاعِيلُ، عَنْ خَالِدٍ الْحَذَّاءِ، عَنْ أَبِي قِلاَبَةَ، عَنْ أَنَسٍ ـ رضى الله عنه ـ قَالَ كَانَ الْقُنُوتُ فِي الْمَغْرِبِ وَالْفَجْرِ.
English translation
Narrated Anas:The qunut [supplication before going down for prostration] used to be recited in the Maghrib and the Fajr prayers
Reference: Sahih al-Bukhari 798, Book of Call to Prayers (Adhaan). English translation by Dr. Muhammad Muhsin Khan.