بُلُوغُ الْمَرَامِ
Bulugh al-Maram 434
The Book of Prayer
وَعَنْهُ قَالَ: { خَرَجْنَا مَعَ رَسُولِ اَللَّهِ - صلى الله عليه وسلم -مِنْ اَلْمَدِينَةِ إِلَى مَكَّةَ، فَكَانَ يُصَلِّي رَكْعَتَيْنِ رَكْعَتَيْنِ حَتَّى رَجَعْنَا إِلَى اَلْمَدِينَةِ } مُتَّفَقٌ عَلَيْهِ, وَاللَّفْظُ لِلْبُخَارِيِّ . [1] .
Narrated [Anas (RA)]: We went from al-Madinah to Makkah with Allah's Messenger (ﷺ) and he prayed two Rak'at at each time of prayer till we returned to al-Madinah. [Agreed upon, and the wording is al-Bukhari's].
Sunnah.com reference: Book 2, Hadith 344