Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
bukhari:1108Ḥusayn > Yaḥyá b. Abū Kathīr > Ḥafṣ b. ʿUbaydullāh b. Anas > Anas b. Mālik

Messenger of Allah ﷺ used to offer these two prayers together on journeys i.e. the Maghrib and the ʿIsha'.  

البخاري:١١٠٨وَعَنْ حُسَيْنٍ عَنْ يَحْيَى بْنِ أَبِي كَثِيرٍ عَنْ حَفْصِ بْنِ عُبَيْدِ اللَّهِ بْنِ أَنَسٍ عَنْ أَنَسِ بْنِ مَالِكٍ ؓ قَالَ

كَانَ النَّبِيُّ ﷺ يَجْمَعُ بَيْنَ صَلاَةِ الْمَغْرِبِ وَالْعِشَاءِ فِي السَّفَرِ وَتَابَعَهُ عَلِيُّ بْنُ الْمُبَارَكِ وَحَرْبٌ عَنْ يَحْيَى عَنْ حَفْصٍ عَنْ أَنَسٍ جَمَعَ النَّبِيُّ ﷺ