The Book of the Times (of Prayer)
6/46. Chapter:
Situations During Which It Is Permissible To Combine Two Prayers
Sunan an-Nasai
أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ أَنْبَأَنَا عَبْدُ الرَّزَّاقِ، قَالَ حَدَّثَنَا مَعْمَرٌ، عَنْ مُوسَى بْنِ عُقْبَةَ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم إِذَا جَدَّ بِهِ السَّيْرُ أَوْ حَزَبَهُ أَمْرٌ جَمَعَ بَيْنَ الْمَغْرِبِ وَالْعِشَاءِ .
It was narrated that Ibn 'Umar said: "If the Messenger of Allah (ﷺ) was in a hurry to travel, or some emergency arose, he would combine Maghrib and 'Isha'."
Reference : Sunan an-Nasa'i 599In-book reference : Book 6, Hadith 106English translation : Vol. 1, Book 6, Hadith 600