Praise be to Allah, and peace and blessings be upon our Prophet Muhammad.
The thing that Allah protected His Prophet from was getting killed, and therefore, he ordered his guards to withdraw after this verse was revealed.
As for getting harmed by the disbelievers, this indeed happened. He was harmed in the Battle of Uhud and other battles.
In addition, as for what he conveys of the matters of religion, he is infallible in it. Allah says {what means}: "Nor does he speak from [his own] inclination." [An-Najm, 3], and Allah says {what means}, "Whoever obeys the Messenger has indeed obeyed Allah." [An-Nisa, 80], and there are many other verses that indicate the obligation to obey him. If there were any flaw in what he says, Allah would not have commanded us to obey him. Bewitchment is like a disease, but Allah cured him from it, and it did not affect what he conveyed to people as far as the rulings of religion are concerned.
Moreover, those who raise doubts are those about whom Allah said {what means}: "They wish to extinguish the light of Allah with their mouths, but Allah will perfect His light, although the disbelievers dislike it. It is He who has sent His Messenger with guidance and the religion of truth to manifest it over all religions, although the polytheists dislike it." [At-Tawbah, 32-33]. We can add that those who doubt should look at other religions to realize that Allah has preserved Islam. And Allah The Almighty knows best.
