Salim told me, "ʿAbdullah bin ʿUmar said, 'I saw Messenger of Allah ﷺ delaying the Maghrib prayer till he offered it along with the ʿIsha prayer whenever he was in a hurry during the journey.' " Salim said, "Abdullah bin ʿUmar used to do the same whenever he was in a hurry during the journey. After making the call for Iqama, for the Maghrib prayer he used to offer three rakʿat and then perform Taslim. After waiting for a short while, he would pronounce the Iqama for the ʿIsha' prayer and offer two rakʿat and perform Taslim. He never prayed any Nawafil in between the two prayers or after the ʿIsha' prayers till he got up in the middle of the night (for Tahajjud prayer)." (Using translation from Bukhārī 1109)   

رَأَيْتُ رَسُولَ اللهِ ﷺ إِذَا أَعْجَلَهُ السَّيْرُ فِي السَّفَرِ يُؤَخِّرُ صَلَاةَ الْمَغْرِبِ حَتَّى يَجْمَعَ بَيْنَهَا وَبَيْنَ الْعِشَاءِ قَالَ سَالِمٌ وَكَانَ عَبْدُ اللهِ بْنُ عُمَرَ يَفْعَلُ ذَلِكَ إِذَا أَعْجَلَهُ السَّيْرُ يُقِيمُ صَلَاةَ الْمَغْرِبِ فَيُصَلِّيهَا ثَلَاثًا ثُمَّ يُسَلِّمُ ثُمَّ قَلَّ مَا يَلْبَثُ حَتَّى يُقِيمَ صَلَاةَ الْعِشَاءِ وَيُصَلِّيهَا رَكْعَتَيْنِ ثُمَّ يُسَلِّمُ وَلَا يُسَبِّحُ بَيْنَهُمَا بِرَكْعَةٍ وَلَا يُسَبِّحُ بَعْدَ الْعِشَاءِ بِسَجْدَةٍ حَتَّى يَقُومَ مِنْ جَوْفِ اللَّيْلِ