Sunan Abi Dawud 1360
سنن أبي داود#1360Sahihحَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا اللَّيْثُ، عَنْ يَزِيدَ بْنِ أَبِي حَبِيبٍ، عَنْ عِرَاكِ بْنِ مَالِكٍ، عَنْ عُرْوَةَ، عَنْ عَائِشَةَ، أَنَّهَا أَخْبَرَتْهُ : أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ يُصَلِّي بِاللَّيْلِ ثَلاَثَ عَشْرَةَ رَكْعَةً بِرَكْعَتَىِ الْفَجْرِ .
Narrated 'Aishah:The Prophet (ﷺ) used to pray thirteen rak'ahs during the night including the two rak'ahs of the dawn prayer
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Muslim (737)
In-book reference: 5:111