I saw on the right side of Allah's Messenger (ﷺ) and on his left side two persons with white clothes on the Day of Uhtid fighting a desperate fight, and I saw them neither before nor after that.
Sahih Muslim Book 43, Hadith 64
← Previous Hadith Sa`d reported that on the Day of Uhud I saw on the right side of Allah's Messenger (ﷺ) and on his left side two persons dressed in white clothes and whom I did not see before nor after that, and they were Gabriel and Michael (Allah be pleased with both of them).

Sahih Muslim Book 43, Hadith 63 Next Hadith → There was nothing to be afraid of, and he also said: We found it (this horse) like a torrent of water (indicating its swift-footedness), whereas the horse had been slow before that time.

Sahih Muslim Book 43, Hadith 65