In the Hadiqat al-Haqiqah, Sana'i establishes a clear distinction between biological brotherhood and spiritual brotherhood. While biological brotherhood is characterized by inherent rivalry, greed over inheritance, and material demands, true spiritual brotherhood is defined by selflessness and a complete lack of possessiveness over worldly wealth. Sana'i argues that while blood relations often bring grief and conflict, spiritual companions transcend material boundaries, proving their sincere love through mutual financial transparency and shared devotion.