It is narrated from Sayyiduna Anas (may Allah be pleased with him), he said that the Prophet (peace and blessings of Allah be upon him) established brotherhood between Sayyiduna Ibn Mas'ud and Sayyiduna Zubair (may Allah be pleased with them both).
Hadith Referenceالادب المفرد / كتاب / 568
Hadith Gradingالألبانی:صحيح
Hadith Takhrij«صحيح : أخرجه البيهقي فى الكبرىٰ : 262/6 - انظر الصحيحة : 3166 - و رواه المصنف فى تاريخه من حديث ابن عباس : 417/8»
Explanation & Benefits
Shaykh Maulana Usman Muneeb
Benefits and Issues: The initial form of brotherhood (mu’akhah) and fraternity was such that they would also become heirs to one another. Then, this arrangement was abrogated, and only the real heirs were made deserving of inheritance. However, Islamic brotherhood was maintained. Therefore, in those ahadith where the negation of alliance (half) and brotherhood is mentioned, what is meant is the negation of becoming heirs to one another.
Source: Fadlullah al-Ahad: Urdu Commentary on al-Adab al-Mufrad, Page: 568