Introduction

Rahmatullah ibn Khalil al-Uthmani al-Kairanawi (1818–1891 CE / 1234–1308 AH) was an Indian Muslim scholar who rose to prominence during one of the most turbulent periods in the history of Islam in the subcontinent. Composing Izhar al-Haqq (The Manifestation of Truth) in the wake of the British-sponsored Christian missionary campaign of the 1850s, he produced a work that would decisively shift the terms of Muslim-Christian debate. When the missionary Karl Gottlieb Pfander published his Mizan al-Haqq attacking Islam and challenging Muslims to public disputation, Kairanawi accepted the challenge. He studied German and English orientalist scholarship intensively, turning the tools of European Biblical criticism against the missionary enterprise itself, and met Pfander in the famous Agra debate of 1854 — an encounter so thorough in its effect that the British authorities cancelled a planned second session.

Izhar al-Haqq is, at its core, a comprehensive demonstration that the Biblical text as it exists today has been subject to human alteration, addition, and loss — what Islamic theology calls tahrif. Kairanawi marshals testimony from Western scholars, textual variants in the manuscript tradition, and internal contradictions between the books of the Bible to establish this point with a thoroughness that no missionary could easily answer. He then proceeds to demonstrate the prophethood of Muhammad ﷺ from both the Old and New Testaments, drawing on the same orientalist scholarship that missionaries used against Muslims and redirecting it toward Islamic conclusions. The work was translated into English and became one of the most widely read Islamic apologetic texts across the Muslim world.

The methodological achievement of Izhar al-Haqq lies in Kairanawi's decision to fight on the opponent's own intellectual terrain. Rather than relying solely on the Quran and Sunnah — which Christian missionaries were predisposed to dismiss — he built his case substantially from the findings of European Biblical scholarship: the Dead Sea Scrolls had not yet been found, but the Codex Sinaiticus had been published, variant readings were a matter of open scholarly debate, and the Documentary Hypothesis regarding the authorship of the Pentateuch was gaining ground. Kairanawi leveraged all of this, making his refutation as effective with Western-educated readers as with traditionally trained ones.

Reading Izhar al-Haqq today requires some historical contextualisation — the missionary landscape of 19th-century India is not identical to contemporary interfaith dynamics — but its core arguments retain their validity and force. The textual evidence Kairanawi marshaled has only been supplemented by subsequent scholarship, not overturned. For Muslims engaged in dawah, interfaith dialogue, or academic comparative religion, the work remains one of the foundational references of the tradition. It models an approach to engagement that is intellectually honest, rigorously evidential, and firmly grounded in the conviction of Islam's truth without recourse to polemical excess.