As for the grading of the ḥadīth, “Why am I disputing with the Qur’an?,” it was narrated by Aḥmad and the compilers of the Sunan; al-Tirmidhī declared it good, and Abū Ḥātim judged it authentic.
As for the wording, “The imam is a guarantor,” this phrase does not appear in that ḥadīth. It is found only in another narration: “The imam is liable and the mu’adhdhin is entrusted.”
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Reciting Sūrah al-Masad in the prayer
Question: We have heard that it is impermissible to recite Sūrah al-Masad in the prayer. Is this correct, and why?
Answer: That is not correct. It is permissible to recite Sūrah al-Masad—in fact any sūrah of the Qur’an—whether inside or outside the prayer. It is a chapter of the Book of Allah, and the Exalted says: “Recite, then, whatever is easy for you of it” (al-Muzzammil 73:20). He did not fix a specific portion of the Qur’an to be recited in the prayer; rather, the entire Qur’an may be recited in the prayer, Sūrah al-Masad included.
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Reciting along with the imam
Question: Whenever I perform any audible prayer in any mosque, I recite behind the imam, keen to follow him so that if he makes a mistake I can correct him. Is there any sin in doing so, or not?