The Proofs and Evidence for the Three Principles

A defining feature of Al-Usul ath-Thalathah is its insistence on evidence. Ibn Abdul Wahhab does not simply state what Muslims must believe — he consistently asks "What is the proof?" (Ma al-dalil?) and supplies the answer from the Quran and authentic Sunnah. This chapter consolidates and explains the methodology of evidence he employs throughout the treatise.

The author distinguishes between two types of knowledge: taqlid (blind imitation without understanding the proof) and ittiba' (following based on understanding the evidence). While taqlid has its place in subsidiary legal matters for the layperson, in matters of foundational creed it is not sufficient. Every Muslim must know not only what to believe but why — grounded in revelation, not merely tradition or cultural habit.

For the first principle — knowledge of Allah — the primary proof is the opening chapter of the Quran itself. Al-Fatiha, recited in every rak'ah of prayer, begins with: "All praise is due to Allah, the Lord of all the worlds." The phrase "Lord of all the worlds" (Rabb al-'alamin) establishes divine lordship over every created thing. Further proof comes from the Verse of the Footstool (Ayat al-Kursi, Al-Baqarah, 2:255), which the Prophet described as the greatest verse in the Quran. It enumerates the attributes of Allah's sovereignty, knowledge, and sustaining power in a manner unmatched by any other verse.

For the oneness of worship specifically, Ibn Abdul Wahhab returns repeatedly to Surah Al-Kafirun ("Say: O disbelievers...") and Surah Al-Ikhlas ("Say: He is Allah, the One..."). These short surahs encapsulate the entire doctrine of tawhid al-uluhiyyah. The Prophet said that Surah Al-Ikhlas is equivalent in reward to one-third of the Quran because of its complete description of Allah's unique oneness (Sahih Bukhari and Muslim).

For the second principle — knowledge of Islam — the proof landscape is broad. The five pillars are each established by clear Quranic commands paired with prophetic narration. The hadith of Jibril (Sahih Muslim) is perhaps the single most important hadith for this chapter, as it encapsulates Islam, iman, and ihsan in one exchange between the Prophet and the angel sent in human form. The Prophet concluded the narration by saying: "That was Jibril who came to teach you your religion."

For the third principle — knowledge of the Prophet — the proof of his prophethood is the Quran: "Muhammad is not the father of any of your men, but he is the Messenger of Allah and the seal of the prophets" (Al-Ahzab, 33:40). The Prophet's own words in the hadith of prophethood (Sahih al-Bukhari) — "I was sent to all of mankind in red and black" — further establish the universal scope of his mission.

Ibn Abdul Wahhab also addresses the question of why evidence matters in practice. He cites the scene of the grave directly: the dead person is asked three questions, and those who answer correctly are those who learned these principles with their proofs during their lives. The Prophet said: "When the believer is questioned in the grave, he will testify that there is no deity worthy of worship but Allah and that Muhammad is the Messenger of Allah — that is the meaning of Allah's statement: 'Allah keeps firm those who believe with a firm word in worldly life and in the Hereafter'" (Al-Baqarah, 2:186 — see Ibrahim, 14:27; narrated in Sahih Bukhari and Muslim).

The chapter concludes with a reminder that evidence-based knowledge produces firm, unshakeable conviction — not just at the hour of death, but in daily life, when doubts are raised, when trials press in, and when the believer must stand firm in a world that constantly challenges the fundamentals of the faith.