How can one respond to those who cite the verse "لَا يَنَالُ عَهْدِي الظَّالِمِينَ" (My covenant does not include the wrongdoers) (Al-Baqarah: 124) to claim a grammatical error in the Qur'an by accusing the subject?

The machinations of the enemies of religion and their attempts to cast doubt on the Qur’an are endless, as confirmed by Allah’s saying: "And never will the Jews or the Christians approve of you until you follow their religion." And His saying: "And they will continue to fight you until they turn you back from your religion, if they are able." And His saying: "They wish that you would disbelieve as they disbelieved, so you would be alike." But Allah is the helper of His religion and the preserver of His Book: "Indeed, those who disbelieve spend their wealth to avert [people] from the way of Allah. So they will spend it; then it will be for them regret; then they will be overcome." And "They want to extinguish the light of Allah with their mouths, but Allah will perfect His light."

Regarding the noble verse, the word "الظالمين" (the wrongdoers) is an object (maf'ul bihi) in the accusative case, marked by the letter 'yaa'. And "عهدي" (My covenant) is the subject (fa'il) in the nominative case, with an implied Damma. The meaning is that Allah's covenant does not include the wrongdoers.