Ibn Shihab, among the names of those who drank the cup of martyrdom at the Battle of Khaybar, mentioned Sayyiduna Mahmud bin Maslamah (may Allah be pleased with him) from the Ansar, who belonged to Banu Harithah. They also mentioned that the Prophet (peace and blessings be upon him) said to Sayyiduna Muhammad bin Maslamah (may Allah be pleased with him): "Your brother will receive the reward of two martyrs." Besides him, from Banu Zurayq, Sayyiduna Mas'ud bin Sa'd bin Qays (may Allah be pleased with him) (drank the cup of martyrdom).
Al-Tabarani recorded it, and its narrators are the narrators of the Sahih.