"Indeed, those who fear Allah—when an impulse from Satan touches them, they remember [Him]." Al-Hasan said: A ta'if (impulse/circulator) is from the act of tawaf (circling); meaning: he circles around them with his whisperings, commanding them to commit disobedience. "And at once they are enlightened [to their error]," meaning: they are repentant from the disobedience.
﴿إِنَّ الَّذِينَ اتَّقَوْا إِذَا مَسَّهُمْ طائف من الشَّيْطَان تَذكرُوا﴾ قَالَ الْحَسَنُ: طائفٌ مِنَ الطُّوفَانِ؛ أَيْ: يَطُوفُ عَلَيْهِمْ بِوَسَاوِسِهِ؛ يَأْمُرُهُمْ بالمعصية ﴿فَإِذا هم مبصرون﴾ أَي: تائبون من الْمعْصِيَة