Sayyiduna Miswar (may Allah be pleased with him) narrates: A Jew passed by me while I was standing behind the Prophet (peace and blessings be upon him), and the Prophet (peace and blessings be upon him) was performing ablution. He said: "Remove the cloth from his back." The narrator says: I began to remove the cloth from his back, and the Prophet (peace and blessings be upon him) sprinkled water on my face.
Ahmad and al-Tabarani recorded it, and its narrators are thiqat (trustworthy).