Brotherhood among the Prophet's Companions

It is narrated from Sayyiduna Anas (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) established brotherhood between Sayyiduna Abu Ubaidah al-Jarrah and Sayyiduna Abu Talhah (may Allah be pleased with them both).

‘Asim Ahwal says that it was said to Sayyiduna Anas bin Malik (may Allah be pleased with him): “Have you heard from the Messenger of Allah (peace and blessings of Allah be upon him) that there is no alliance (hilf) in Islam?” So Sayyiduna Anas (may Allah be pleased with him) said: “Indeed, the Messenger of Allah (peace and blessings of Allah be upon him) made an alliance between the Quraysh and the Ansar in his house.”

Jubair bin Mut’im (may Allah be pleased with him) reports that the Messenger of Allah (peace and blessings be upon him) said: There is no alliance in Islam (i.e., such an alliance in which there is partnership even in inheritance, etc.), and any oath that was taken in the time of ignorance (for a good cause) has become even stronger with Islam.