The Secret Counsel of Quraysh after hearing the Qur'an
Allah tells His Prophet about what the leaders of Quraysh discussed when they came and listened to him reciting Qur'an in secret, without their people knowing about it. They said that he was Mashur which according to the better-known view means someone affected by magic (Sihr); it may also mean a man who has a lung, i.e., a mere human being, as if they were saying that if you follow Muhammad, you will only be following a human being. This second suggestion does not sound correct, because what they meant here was that he was under the influence of Sihr (magic) which made him see dreams in which he learned these words that he recited. Some of them said he was a poet, or a soothsayer, or crazy, or a sorcerer. Allah says:
A prophet being affected by magic is as possible as being affected by sickness. Therefore, blessed prophets are not devoid of or detached from human characteristics. For instance, they could be wounded, run temperature or feel pain. Similarly, they could also be affected by magic because, that too, is triggered by the influence of physical causes, such as those of the Jinn. And it also stands proved from Hadith that there was an occasion when the Holy Prophet ﷺ was affected by magic. As for the disbelievers calling him 'bewitched' ('mashur' ) in verse 47 which the Qur'an has refuted for the reason that they really meant to call him 'insane.' (Bayan al-Qur'an) Therefore, the Hadith of magic is not contradictory.1
The call of the Prophet Muhammad was supported by such strong arguments that the common people of Arabia were awed by it. Seeing this, the Arab leaders felt afraid that, if the majority of the people converted to the new religion, their leadership would come to an end. They, therefore, employed a strategy to keep people away from it. They said that the great impact the Prophet’s words had was due to his being possessed. They said, moreover, that the power of his words did not stem from his having discovered some truth, but from his possessing magical powers. That is, it was a mere matter of oratorical prowess rather than the communication of truth. In this way the majestic words of the Quran reflecting Truth came to mean to them a magic spell wrought by an individual. Those who fail to judge such a call on the basis of its merit but look at it rather from the point of view of whether the words of the call support or reject their own stand, shall never succeed in finding the truth.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.