Surah Yunus (10) — Ayah 2

2. Is it astonishing to people [2] that We have revealed to a man from among them, (saying) that he should warn the people [3] and give good news to those who believe that they have a true rank and honor with their Lord? The disbelievers say, "Indeed, this is surely a clear [4] magician."

[2]
Only a Human Can Be a Messenger for the Guidance of People:

Their first objection was: how is it possible that this person, who is just a man like us, who lives his life just as we do, eats, drinks, and walks in the markets like us, could be the Messenger of Allah? Allah Almighty has answered this at numerous places: that for the guidance of mankind, only a human can be a Messenger, one who speaks and understands their language. No other way was possible; neither could an angel be made a Messenger, nor a jinn or any other creature. And even if that were done, how could it be a proof against the people?
[3] The purpose of sending this Messenger is that he may timely inform people of their evil end, convey to them all the commands of Allah, and make it clear that honor and elevation are only for those who accept his teachings. Therefore, people should reflect: what is it, after all, that they are astonished about?
[4]
Why Were You Called a Magician?

Because the speech of Allah that you presented was so subtle, sweet, and effective that even the disbelievers would become enchanted upon hearing it. As the Noble Prophet ﷺ himself said: «اِنَّ مِنَ الْبَيَان لسحرًا» [بخاري بحواله مشكوة۔ كتاب الآدب۔ باب البيان والشعر فصل اول]
That is, some speech is such that it works like magic. Because of this effect of the Quran, the Quraysh had forbidden the recitation of the Quran aloud, saying that it would influence their women and children. However, those very Qurayshi chiefs who imposed this ban would themselves enjoy listening to the Quran and, despite their mutual agreement, would secretly listen to it.

The Story of Dhamad Azdi Accepting Islam:

Once, Dhamad Azdi, an influential member of the tribe of Azd from Yemen, came to Makkah. The chiefs of Quraysh warned him that there is a man here, Muhammad ﷺ, whose speech is magical—beware lest you fall into his hands. Dhamad Azdi himself practiced spiritual healing, so he thought he should listen to this man. After all, he was a sensible man; if he liked what he heard, he would accept it, otherwise he would leave it. And it was also possible that if Muhammad ﷺ was afflicted by something, Allah might cure him at his hands. With this thought, he went to the Prophet ﷺ and requested to hear his speech. The Prophet ﷺ recited to him the Khutbah Masnunah up to «الحمد لله... عبده و رسوله». Although this sermon is not a separate Quranic verse, it is a collection of Quranic words. When Dhamad heard these words, he was moved and said, "Repeat it." The Prophet ﷺ repeated it, and he said, "Repeat it once more." When the Prophet ﷺ repeated these words a third time, he said, "I have heard the speech of soothsayers and magicians, and I have heard the verses of poets, but I have never heard anything like these words before. Surely, these words have reached the depths of the sea." Then he extended his hand to pledge allegiance, and the Prophet ﷺ said, "And on behalf of your people?" Dhamad replied, "Yes, I pledge allegiance on behalf of my people as well." [مسلم، كتاب الجمعه، باب تخفيف الصلوة والخطبة]
Dhamad Azdi's statement, "These words have reached the depths of the sea," is the same as what Allah Almighty has said in the first verse of this Surah: ﴿تِلْكَ اٰيٰتُ الْكِتٰبِ الْحَكِيْمِ﴾—that is, this Book is so full of wisdom that every statement is based on reasoning and leads to its logical conclusion, and its eloquence, subtlety, and sweetness are additional beauties. And since it was this very Quran that the Prophet ﷺ was presenting, which would enchant people, the disbelievers would call the Prophet ﷺ a magician. Most of the Prophets and Messengers who were given any tangible miracle were given this same title by the disbelievers. However, there is a world of difference between the life of a Messenger and that of a magician. For example:

1.
The Difference Between a Prophet and a Magician:

Magic is an art that is acquired through learning; every magician is a disciple of a teacher, whereas a miracle is granted solely by Allah—it is not something that can be learned or taught.
2. Magic is a profession adopted for the acquisition of wealth and riches, and in this matter, magicians are of extremely low mentality. As when Pharaoh summoned the magicians, their first question was, "Will we get any reward for this?" Whereas a Prophet serves humanity selflessly and openly declares to the people that he asks for no reward from them.
3. Magic is generally performed for things that are intended to harm or cause pain to someone, whereas a miracle is presented as a sign of Prophethood for the guidance of people, and its purpose is pure goodness.
4. The morals and character of a magician are both despicable, and if people respect them, it is only to protect themselves from their evil. Whereas the morals and character of the Prophets are extremely pure, and it is on this basis that they are respected, and their past life is presented as a standard before the disbelievers. Despite such clear differences, if the opponents continued to call the Prophets magicians, it was not because they could not see such an obvious distinction, but rather due to their stubbornness, obstinacy, enmity, prejudice for the religion of their forefathers, and fear of losing their positions and leadership, etc.