Saʿd reported that on the Day of Uhud I saw on the right side of Messenger of Allah 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). (Using translation from Muslim 2306a)
عَنْ يَمِينِ رَسُولِ اللهِ ﷺ وَعَنْ شِمَالِهِ يَوْمَ أُحُدٍ رَجُلَيْنِ عَلَيْهِمَا ثِيَابٌ بِيضٌ لَمْ أَرَهُمَا قَبْلُ وَلا بَعْدُ