Sayyiduna Abdul Rahman bin Awf (may Allah be pleased with him) migrated to the Prophet (peace and blessings be upon him), and the Messenger of Allah (peace and blessings be upon him) established brotherhood between him and Sa'd bin al-Rabi' (may Allah be pleased with him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الفرائض / 12519