The Book of the Times (of Prayer)
6/45. Chapter:
The Time When A Traveler May Combine Maghrib and 'Isha'
Sunan an-Nasai
أَخْبَرَنِي عَمْرُو بْنُ عُثْمَانَ، قَالَ حَدَّثَنَا بَقِيَّةُ، عَنِ ابْنِ أَبِي حَمْزَةَ، ح وَأَنْبَأَنَا أَحْمَدُ بْنُ مُحَمَّدِ بْنِ الْمُغِيرَةِ، قَالَ حَدَّثَنَا عُثْمَانُ، - وَاللَّفْظُ لَهُ - عَنْ شُعَيْبٍ، عَنِ الزُّهْرِيِّ، قَالَ أَخْبَرَنِي سَالِمٌ، عَنْ أَبِيهِ، قَالَ رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم إِذَا أَعْجَلَهُ السَّيْرُ فِي السَّفَرِ يُؤَخِّرُ صَلاَةَ الْمَغْرِبِ حَتَّى يَجْمَعَ بَيْنَهَا وَبَيْنَ الْعِشَاءِ .
It was narrated that Az-Zuhri said: "Salim told me that his father said: 'I saw the Messenger of Allah (ﷺ), when he was in a hurry to travel, delaying Maghrib so that he could combine it with 'Isha'.'"
Reference : Sunan an-Nasa'i 592In-book reference : Book 6, Hadith 99English translation : Vol. 1, Book 6, Hadith 593