Whenever the Messenger of Allah ﷺ was pressing on with his journey, he would combine the sunset and night prayers.
أخبرنا قتيبة بن سعيد عن مالك عن نافع
أن رسول الله ﷺ كان إذا جد به السير جمع بين المغرب والعشاء
Muslim narrated it in "Prayer of the Traveler, chapter on the permissibility of combining the two prayers while traveling," hadith no. 42/703, from the hadith of Malik through this same chain. It is also found in Muwatta (Yahya's version) 1/114, and in Kubra, hadith no. 1572.