Kathir, the freed slave of Umar bin al-Khattab (may Allah have mercy on him), said: I heard Sayyidah Aishah (may Allah be pleased with her) say: I saw the Messenger of Allah (peace and blessings be upon him) standing with the rider of a white horse, and he (peace and blessings be upon him) was holding the mane of his horse. When he (peace and blessings be upon him) came to me, I asked: Who was the man with the horse? He (peace and blessings be upon him) said: "Did you see him?" I said: Yes. He (peace and blessings be upon him) said: "Whom did he resemble?" I said: Dihyah bin Khalifah al-Kalbi. He (peace and blessings be upon him) said: "That was Jibril, and he is conveying his greeting of peace to you." I said: And peace be upon the One who sent him, and upon you, and upon him.
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19389