بُلُوغُ الْمَرَامِ
Bulugh al-Maram 388
The Book of Prayer
وَلِابْنِ حِبَّانَ: { مَنْ أَدْرَكَ اَلصُّبْحَ وَلَمْ يُوتِرْ فَلَا وِتْرَ لَهُ } [1] .
Ibn Hibban has: 'Whosoever reaches the dawn, and he did not offer Witr, then there is no Witr for him.'
Sunnah.com reference: Book 2, Hadith 292