(4) باب لِيَجْعَلْ آخِرَ صَلاَتِهِ وِتْرًا
Narrated `Abdullah bin `Umar:
The Prophet (ﷺ) said, "Make witr as your last prayer at night."
Reference: Sahih al-Bukhari 998
In-book reference: Book 14, Hadith 9
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 2, Book 16, Hadith 112