Is a person considered sinful if they are assailed by satanic thoughts while reciting the Holy Quran? And what should one do about that?

We advise you to continue reciting the Quran and to strive against the satanic whispers that aim to divert you from the Book of Allah. For Allah does not hold one accountable for what passes through the heart unless it is firmly intended. The levels of what passes through the mind vary: a fleeting thought (al-hajis), a sudden thought (al-khatir), and self-talk (hadith (definition) al-nafs) are not held against one. As for intending a good deed, it is written as a good deed. Intending a bad deed is not written as a bad deed unless it is acted upon. However, regarding the firm intention to commit a sin, verified scholars believe one is held accountable for it, based on the Hadith, "If two Muslims meet each other with their swords," and on accountability for actions of the heart such as envy, and Allah’s saying: "And whoever intends therein [i.e., within the sacred precincts of Makkah] to deviate with injustice - We will make him taste of a painful punishment."