Shortening the Prayers (At-Taqseer)
18/11. Chapter:
Whoever did not offer the Nawafil before and after the (compulsory) Salat during a journey
Sahih Bukhari
حَدَّثَنَا مُسَدَّدٌ، قَالَ حَدَّثَنَا يَحْيَى، عَنْ عِيسَى بْنِ حَفْصِ بْنِ عَاصِمٍ، قَالَ حَدَّثَنِي أَبِي أَنَّهُ، سَمِعَ ابْنَ عُمَرَ، يَقُولُ صَحِبْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم فَكَانَ لاَ يَزِيدُ فِي السَّفَرِ عَلَى رَكْعَتَيْنِ، وَأَبَا بَكْرٍ وَعُمَرَ وَعُثْمَانَ كَذَلِكَ ـ رضى الله عنهم.
Narrated Ibn `Umar: I accompanied Allah's Messenger (ﷺ) and he never offered more than two rak`at during the journey. Abu Bakr, `Umar and `Uthman used to do the same.
Reference : Sahih al-Bukhari 1102In-book reference : Book 18, Hadith 22USC-MSA web (English) reference : Vol. 2, Book 20, Hadith 206