Language:
كتاب الوتر
14  
Witr Prayer
(7)
Chapter: To recite Qunut before and after bowing
(7)
باب الْقُنُوتِ قَبْلَ الرُّكُوعِ وَبَعْدَهُ
Sahih al-Bukhari 1001

Narrated Muhammad bin Seereen:

Anas was asked, "Did the Prophet (ﷺ) recite Qunut in the Fajr prayer?" Anas replied in the affirmative. He was further asked, "Did he recite Qunut before bowing?" Anas replied, "He recited Qunut after bowing for some time (for one month)."

حَدَّثَنَا مُسَدَّدٌ، قَالَ حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، عَنْ أَيُّوبَ، عَنْ مُحَمَّدٍ، قَالَ سُئِلَ أَنَسٌ أَقَنَتَ النَّبِيُّ صلى الله عليه وسلم فِي الصُّبْحِ قَالَ نَعَمْ‏.‏ فَقِيلَ لَهُ أَوَقَنَتَ قَبْلَ الرُّكُوعِ قَالَ بَعْدَ الرُّكُوعِ يَسِيرًا‏.‏
Reference : Sahih al-Bukhari 1001
In-book reference : Book 14, Hadith 12
USC-MSA web (English) reference : Vol. 2, Book 16, Hadith 115
  (deprecated numbering scheme)