Musnad Ahmad 1290:0

Narrated to us by Yahya ibn Sa’id, from Sufyan, who said: Narrated to me Abu al-Zinad, from al-Kharijah ibn Zayd ibn Thabit, from Umm al-‘Ala’, a woman who had pledged allegiance to the Prophet (ﷺ), she said: The Ansar drew lots regarding the housing of the Emigrants (Muhajirun). We were allotted Uthman ibn Maz’un, and we let him stay in our houses. We served him and provided for him, but he fell ill and passed away. When he died, we shrouded him in his garments. The Messenger of Allah (ﷺ) entered upon us, and I said: "May the mercy of Allah be upon you, O Abu al-Sa’ib! I bear witness that Allah has honored you." The Prophet (ﷺ) said: "How do you know that Allah has honored him?" I said: "I do not know, may my father and mother be sacrificed for you, O Messenger of Allah. But who else would Allah honor?" The Prophet (ﷺ) said: "As for him, by Allah, certainty has come to him from his Lord, and I truly hope for good for him. But by Allah, although I am the Messenger of Allah, I do not know what will be done with me." Umm al-‘Ala’ said: "By Allah, I will never praise anyone after him." She said: "I then saw in a dream that Uthman had a flowing spring. I went to the Prophet (ﷺ) and mentioned that to him. He said: 'That is his deed [continuing to flow for him].'"