(27) بَابُ مَا يُقْرَأُ فِي رَكْعَتَيِ الْفَجْرِ
Narrated `Aisha:
Allah's Messenger (ﷺ) used to offer thirteen rak`at in the night prayer and on hearing the Adhan for the morning prayer, he used to offer two light rak`at.
Reference: Sahih al-Bukhari 1164
In-book reference: Book 19, Hadith 43
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 2, Book 21, Hadith 261