كتاب الصلاة
2  
The Book of Prayer
Bulugh al-Maram 388
Ibn Hibban has:
'Whosoever reaches the dawn, and he did not offer Witr, then there is no Witr for him.'
وَلِابْنِ حِبَّانَ: { مَنْ أَدْرَكَ اَلصُّبْحَ وَلَمْ يُوتِرْ فَلَا وِتْرَ لَهُ } 1‏ .‏
Reference : Bulugh al-Maram 388
In-book reference : Book 2, Hadith 388
English translation : Book 2, Hadith 383
Hadith Text
Reference