Muhammad ibn Abd al-Wahhab did not write Kitab al-Tawhid as an argument built mainly from his own reasoning. The treatise is constructed largely from quotations, verses of the Quran, hadith of the Prophet, and sayings of early Muslims, assembled and arranged rather than expounded at length in the author's own voice. That method is itself a claim: by building his case almost entirely out of received text, Ibn Abd al-Wahhab presented tawhid, the strict oneness of God, not as his personal theological position but as something the earliest and most authoritative sources of Islam already said plainly, if anyone would only read them without the accretions he believed had grown up around them.
Working from the Najd region of the Arabian Peninsula, centered on Diriyah, he directed that method at devotional practices he found widespread there, above all the veneration of tombs, saints and intermediaries, which he read as shirk, the association of partners with God, and as a relapse into the pre-Islamic condition Islamic tradition calls jahiliyya. No source consulted for this article gives a firm single year for the treatise's composition; what is well established is the setting, an eighteenth century Najdi preaching career built on the claim that scripture, read plainly, already settled the question.