Tawḥīd, “making one”, is the declaration that there is no god but God. Theologians defined it as God’s uniqueness; the Sufis deepened it, teaching that true tawḥīd is to see nothing but God, until the seeker’s own separate existence falls away. ʿAṭṭār made it the fifth of his seven valleys.
Tawḥīd
The oneness of God: the central affirmation of Islam, which Sufis seek to realize as lived experience.
Also: Tawhid