Is thinking about the Holy Quran during prayer considered an oversight of it, and what are the things permitted to be thought about during prayer without being considered an oversight?

Thinking about the Qur’an during prayer is not a lapse, but rather it is recommended to increase devotion, provided that it does not lead to distraction from the pillars, duties, and Sunnahs of prayer. One must be mindful of Allah’s observation and His greatness, and focus on the prayer while performing the pillars with tranquility and moderation, and avoid thinking about worldly matters. As for thinking about matters of the Hereafter, there is no harm in it.