Is reciting specific surahs after the Fajr and Maghrib prayers to expel the dominion of Satan considered a Bid‘ah (innovation), or is it knowledge bestowed by Allah upon one of His servants?

Reciting the Qur'an is a great act of worship, but a Muslim should not commit to reading a specific surah at a particular time, believing that there is a special legal merit for that act without evidence. This is because it falls under the category of an "added innovation" (bid'ah idafiyyah). Weak hadiths have been reported regarding the daily recitation of Surahs Yasin and Ad-Dukhan. Therefore, strive to recite the Qur'an as much as you can, for there is a great reward in that, without specializing or committing to reading specific surahs at a specific time.