It is narrated from Sayyiduna Sandar Abu Abdullah (may Allah be pleased with him), who was the slave of Zinba' bin Salamah al-Judhami, that he (Zinba') became angry with him, so he castrated him and cut off his nose and ears. Sandar (may Allah be pleased with him) came to the Messenger of Allah (peace and blessings be upon him) and told him (peace and blessings be upon him), so he (peace and blessings be upon him) spoke harshly to Zinba' and freed him from him. Sandar (may Allah be pleased with him) said: O Messenger of Allah, make a bequest concerning me. He (peace and blessings be upon him) said: "I make a bequest concerning every Muslim."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6696