What should a worshiper do if their mind wanders during the Imam's recitation of long surahs, and is it permissible for them to repeat Quranic verses or supplications, or must they listen to the Imam's recitation?

Repel worldly thoughts during prayer, listen to the Imam's recitation, and reflect on its meanings to ward off obsessions. Recite Al-Fatiha and a surah or verses from the Quran with contemplation, hoping that Allah will thereby prevent distraction. It is also prescribed to seek refuge in Allah from Satan, the accursed, when whispers become frequent.