The rebukes in the Quran do not undermine prophetic authority; they define it. Prophets are protected in delivering Allah's message, while remaining human servants whom Allah may correct in public so the religion is not confused with personal impulse.
The strongest form of the objection
The objection has real force if "infallibility" is taken to mean that a prophet can never make any mistake of any kind. The Quran says to the Prophet Muhammad (PBUH):
"O Prophet, why do you prohibit what Allah has made lawful for you, seeking the approval of your wives? And Allah is Forgiving and Merciful."
Quran 66:1
And the hadith reports that he once forgot in prayer and said:
"I am only a human being like you, and I forget as you forget. So if I forget, remind me."
Sahih al-Bukhari 401
The Quran also narrates that Moses killed a man:
"So Moses struck him and killed him. He said, 'This is from the work of Satan. Indeed, he is a manifest, misleading enemy.'"
Quran 28:15
So the critic asks: if prophets can be rebuked, forget, and commit wrong acts, how can Muslims say they are protected? And if the Prophet (PBUH) "speaks only revelation," how can he ever make a human error?
What prophetic protection actually means
The classical doctrine of 'ismah was never that prophets are gods, angels, or incapable of every ordinary human lapse. It means they are protected from lying about Allah, protected in conveying revelation, protected from disgraceful moral corruption, and not left upon error in matters of religion. If a prophetic judgement needs correction, Allah corrects it. That correction itself becomes part of revelation.
This is why the Quran's rebukes are not a weakness in the doctrine. They are one of its proofs. If the Prophet Muhammad (PBUH) had invented the Quran, he would not have preserved verses correcting him, recited forever in worship. The correction shows that the message is above the Messenger's personal preference.
Surah al-Tahrim is correction, not failed revelation
In Quran 66:1, the Prophet (PBUH) did not declare a permanent law for the whole community that Allah then failed to protect. He refrained from something lawful for a personal reason, seeking to please members of his household. Allah corrected him because prophets are models, and even a personal abstention by him could be misunderstood as religious prohibition.
Notice the verse ends, "And Allah is Forgiving and Merciful." That language is gentle correction, not accusation of false prophethood. It teaches that lawful things are not made unlawful by personal pressure, even for the noblest of people.
Forgetting in prayer and Moses' killing
The Prophet's (PBUH) forgetfulness in prayer was not a corruption of revelation. It happened openly, was corrected immediately, and became the basis for teaching the rulings of forgetfulness in prayer. His words, "I forget as you forget," affirm his humanity; they do not mean he forgets revelation in a way that destroys the religion.
As for Moses, the killing occurred before his mission as a messenger, and the verse itself presents it as an unintended blow in a fight, not premeditated murder. Moses repented and sought forgiveness. The Quran does not hide the moral seriousness of the act, but neither does it turn it into proof that Moses later conveyed revelation unreliably.
What this does and does not prove
These examples prove that prophets are human, can be corrected, may make non-legislative mistakes, and may be rebuked by Allah for the sake of perfect guidance. They do not prove that prophets fabricate revelation, teach false religion, persist in sin, or that Allah leaves the community bound to their uncorrected errors.
The Muslim claim is precise: prophetic authority is trustworthy because Allah guards the message, not because prophets are independent of Allah's correction. Their humanity is real, and their guidance is secure.