Urwah narrates: Sayyiduna Sa'd bin Mu'adh (may Allah be pleased with him) sent Sayyiduna al-Harith bin Aws bin al-Nu'man (may Allah be pleased with him), who belonged to Banu Harithah; he sent him along with Sayyiduna Muhammad bin Maslamah (may Allah be pleased with him) to Ka'b bin al-Ashraf. When they struck Ka'b bin al-Ashraf, the tip of the sword struck the leg of al-Harith bin Aws, and his companions carried him back.
Al-Tabarani recorded it. Its chain contains Ibn Lahi'ah, and his hadith is hasan (good).