Sunan an-Nasa'i 492
سنن النسائي#492SahihIt was narrated that Ibn 'Umar said:"The Messenger of Allah (ﷺ) used to pray on his mount while on a journey, no matter what direction it was facing." Malik said: "Abdullah bin Dinar said: 'And Ibn 'Umar used to do likewise
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih - Agreed Upon
In-book reference: 5:45