كتاب المغازى
64  
Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
(35)
Chapter: The Ghazwa of Al-Hudaibiya
(35)
باب غَزْوَةِ الْحُدَيْبِيَةِ
Sahih al-Bukhari 4176

Narrated Abu Jamra:

I asked Aidh bin `Amr, who was one of the companions of the Prophet (ﷺ) one of those (who gave the allegiance to the Prophet (ﷺ) the Tree: "Can the witr prayer be repeated (in one night)?" He said, "If you have offered it in the first part of the night, you should not repeat it in the last part 'of the night." (See Fath-ul-Bari page 458 Vol 8th).

حَدَّثَنَا مُحَمَّدُ بْنُ حَاتِمِ بْنِ بَزِيعٍ، حَدَّثَنَا شَاذَانُ، عَنْ شُعْبَةَ، عَنْ أَبِي جَمْرَةَ، قَالَ سَأَلْتُ عَائِذَ بْنَ عَمْرٍو ـ رضى الله عنه ـ وَكَانَ مِنْ أَصْحَابِ النَّبِيِّ صلى الله عليه وسلم مِنْ أَصْحَابِ الشَّجَرَةِ هَلْ يُنْقَضُ الْوِتْرُ قَالَ إِذَا أَوْتَرْتَ مِنْ أَوَّلِهِ، فَلاَ تُوتِرْ مِنْ آخِرِهِ‏.‏
Reference : Sahih al-Bukhari 4176
In-book reference : Book 64, Hadith 218
USC-MSA web (English) reference : Vol. 5, Book 59, Hadith 493
  (deprecated numbering scheme)