When the Messenger of Allah (ﷺ) was in a state of hurry on a journey, he combined the sunset and 'Isha' prayers.
Sahih Muslim Book 6, Hadith 52
← Previous Hadith We met Anas b. Malik as he came to Syria at a place known as 'Ain-al-Tamar and saw him observing prayer on the back of his donkey with his face turned in that direction. (Hammam one of the narrators) pointed towards the left of Qibla, so I said to him: I find you observing prayer towards the side other than that of Qibla. Upon this he said: Had I not seen the Messenger of Allah (ﷺ) doing like this, I would not have done so at all.

Sahih Muslim Book 6, Hadith 51 Next Hadith → Nafi' reported that when Ibn 'Umar was in a state of hurry on a journey, he combined the sunset and 'Isha' prayers after the twilight had disappeared, and he would say that when the Messenger of Allah (ﷺ) was in a state of hurry on a journey, he combined the sunset and 'Isha' prayers.

Sahih Muslim Book 6, Hadith 53