It was narrated that Ibn 'Abbas said:
"We used to travel with the Messenger of Allah (ﷺ) between Makkah and Al-Madinah, fearing nothing but Allah, the Mighty and Sublime, and praying two rak'ahs."
Reference: Sunan an-Nasa'i 1436
In-book reference: Book 15, Hadith 4
English translation: Vol. 2, Book 15, Hadith 1437