( بِمَجْنُونٍ … ) (…a madman): The madman is the person whose mind is out of order; who does things without any purpose and his speech lacks harmony. Whereas, the sane person who does things purposely and knows his goals. In fact, the Prophet Muhammad (saws) was not the only Prophet who was accused of madness, many Prophets were accused of madness as well. Allah (swt) is relieving the Prophet (saws) saying (Your are not by the favour of your Lord, a madman).
(The favour) refers to the Book and the Wisdom that were revealed to the Prophet (saws). It is the right path that Allah (swt) guided him (saws) to it. The one who got the favour of Allah (swt) can never be a madman, as the mad person acts without logic. Moreover, the words of the Holy Quran are not the words of soothsayers, as the Prophet (saws) was brought among his people who knew for sure that he is truthful and honest and that none has taught him. Besides, the words of soothsayers have special tones and specifications that are different from the words of the Holy Quran. If each two of them should sit and think, they will realize for certain that his (saws) acts have nothing to do with madness for the Prophet’s behaviour is logic and lead him to good actions, definitely he (saws) is not mad or magician. These two characteristics are very far from the Prophet (swt) character and their sign have never appeared in his behaviours. Thus, Allah (swt) in this verse relieves the heart of the Prophet (saws) from his sadness due to their accuse for he (saws) innocent from what they said.