His statement, “If he is able to correct it, his prayer is invalid,” means that if the unlettered person is able to correct the grammatical error that alters the meaning but does not correct it, then his prayer is invalid. If he is unable to do so, then his prayer is valid, though he may lead only one like himself.

However, the correct view is that his leading the prayer is valid in this case, because he is excused due to his inability to recite al-Fātiḥah correctly. Allah Most High says:

“So fear Allah as much as you are able.”

And He says:

“Allah does not burden a soul beyond its capacity.”

In some rural areas there are people who are unable to pronounce al-Fātiḥah correctly. You may hear one of them reciting, “ahdanā,” and he may be unable to recite anything other than what he has grown accustomed to. The prayer of one who is incapable of correcting the grammatical error is valid. As for one who is able to do so, his prayer is invalid, as the author stated, if the error alters the meaning.

THE LEADING OF ONE WHO MAKES FREQUENT GRAMMATICAL ERRORS IS DISLIKED

His statement, “The leading of one who makes frequent grammatical errors is disliked”: one who makes frequent grammatical errors is called a laḥḥān. What is meant here is errors outside al-Fātiḥah. If the error occurs in al-Fātiḥah and alters the meaning, he becomes unlettered, and his leading the prayer is invalid according to the school of law. But if he frequently makes grammatical errors outside al-Fātiḥah, his leading the prayer is valid, though disliked.

The evidence is the saying of the Prophet, may Allah bless him and grant him peace: “The one most proficient in the Book of Allah should lead the people in prayer.” (1) This is a declarative statement intended as a command. Thus, if one who is not the most proficient among them leads them, they have gone against the command