Both Hakim Sana'i in the Hadiqat al-Haqiqah and Farid al-Din Attar in The Conference of the Birds formulate absolute Divine Unity (Tawhid) as a reality transcending numerical representation. Sana'i's description of God being beyond numbers ('one within one is one') directly informs Attar's description of the Valley of Unity, where all numbers dissolve into the absolute One. However, while Sana'i focuses on the epistemological limits of the human intellect ('aql) in comprehending this unity, Attar emphasizes the mystical journey and the spiritual experience of the wayfarer traversing the valley.