Sahih al-Bukhari 1107
Sahih al-Bukhari · Book 18: Shortening the Prayers (At-Taqseer) · To offer Maghrib and "Isha" prayers together on a journey
Narrated Ibn `Abbas:
وَقَالَ إِبْرَاهِيمُ بْنُ طَهْمَانَ عَنِ الْحُسَيْنِ الْمُعَلِّمِ ، عَنْ يَحْيَى بْنِ أَبِي كَثِيرٍ ، عَنْ عِكْرِمَةَ ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَجْمَعُ بَيْنَ صَلاَةِ الظُّهْرِ وَالْعَصْرِ إِذَا كَانَ عَلَى ظَهْرِ سَيْرٍ، وَيَجْمَعُ بَيْنَ الْمَغْرِبِ وَالْعِشَاءِ.
Allah's Messenger (ﷺ) used to offer the Zuhr and `Asr prayers together on journeys, and also used to offer the Maghrib and `Isha' prayers together. Narrated Anas bin Malik: The Prophet (ﷺ) used to offer the Maghrib and the `Isha' prayers together on journeys.