What is the reason for some of the Salaf audibly sighing upon hearing verses of the Qur’an, even though this was not reported of the Prophet (peace be upon him) and his companions?

The reason for fainting and swooning during remembrance (dhikr) and listening to the Quran is due to the intensity of the spiritual incoming (al-warid) and the heart's weakness in bearing it. The hearts of the predecessors (Salaf) were stronger in enduring these faith-based incoming states without experiencing such symptoms. Sheikh al-Islam Ibn Taymiyyah clarified that these states vary depending on the strength of the incoming and the weakness of the heart. For someone who does not experience this, it might be due to the perfection of their strength and faith, or it might be due to the weakness of their faith. These states are not inherent requirements of the spiritual path, nor are they the ultimate goal. Perfection lies in distinguishing between the Creator and the created, and witnessing the meanings of Allah's names and attributes without distraction. Ibn al-Qayyim explained that the state of Prophet Muhammad (peace be upon him) was more perfect than that of Moses (peace be upon him), as his heart remained firm and his gaze did not waver on the Night of Ascension (Mi'raj), whereas Moses fainted when his Lord manifested Himself to the mountain. This indicates that people of sainthood (wilayah) differ according to the strength of their hearts.