Hasan bin Zakariya Farsi says: Once Messenger of Allah (s) and Hazrat Ali (a) went out on some mission. The Holy Prophet (s) was riding a horse, while Ali (a) was on foot. In due course they reached a pool where they performed ablution and recited the prayer.
Hazrat Ali (a) says: I was between the Ruku and Sajdah, when I heard someone saying:
“Ali, lift your head and see. A gift from the Almighty has arrived for you.”
Ali (a) says: When I looked up I saw a horse fully saddled and bridled.
Then the caller said: This is a gift to you from Allah. Mount and ride it.
Ali (a) says: So after I concluded the prayer, I mounted that animal and rode it.2
2 Kitabul Iqbal, Sayyid Ibne Tawus, Pg. 585-586; Biharul Anwar, Vol. 43, Pg. 118, Tr. 26-27; Awalim, Vol. 11, Pg. 156, Tr. 6-7; Kashful Ghumma, Vol. 1, Pg. 275.