On traveling, `Abdullah bin `Umar used to offer the prayer on his Mount by signs whatever direction it took. `Abdullah said that the Prophet (ﷺ) used to do so.
Sahih al-Bukhari Book 18, Hadith 16
← Previous Hadith Ibn `Umar (while on a journey) used to offer the prayer and the witr on his mount (Rahila). He said that the Prophet (ﷺ) used to do so.

Sahih al-Bukhari Book 18, Hadith 15 Next Hadith → I saw the Prophet (ﷺ) on his Mount praying Nawafil by nodding his head, whatever direction he faced, but Allah's Messenger (ﷺ) never did the same in offering the compulsory prayers.

Sahih al-Bukhari Book 18, Hadith 17