Surah 48:1–2
Indeed, We have given you a clear conquest. That Allah may forgive for you what preceded of your sin and what will follow and complete His favor upon you and guide you to a straight path.
Verse 2 states that this "victory" was granted explicitly so that God could "forgive for you what preceded of your sin (thanbika) and what will follow."
The Theological Conflict: This text strikes a direct, fatal blow to the later orthodox Islamic doctrine of Ismah—the belief that prophets are divinely preserved from committing sins or moral failures. The Arabic text uses the word thanb, which explicitly denotes an offensive act, crime, or sin requiring forgiveness.
The Critical Verdict: If Muhammad were ontologically incapable of sinning, the divine promise to forgive his past and future sins is textually absurd. The verse treats the Prophet as a deeply human, flawed agent who accumulation of moral liabilities requires ongoing divine erasure. The doctrine of absolute sinlessness is exposed as a retroactive theological invention of 9th-century jurists, designed to elevate the Prophet’s legal status far beyond the boundaries established by the contemporary Quranic text.