ENOfficial
It was narrated from Ibn 'Umar that if the Messenger of Allah (ﷺ) was in a hurry to travel, he would combine Maghrib and 'Isha'.
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ إِذَا جَدَّ بِهِ السَّيْرُ جَمَعَ بَيْنَ الْمَغْرِبِ وَالْعِشَاءِ .
sunnah.com