There was an affluent man who lived in Mecca, it was said that he is wiser and more intelligent than everyone in Mecca at that time. He used to be a linguistic, eloquent and fluent. Once opponents came to meet him and told him: go to that man (the holy Prophet) and meet him then tell your idea about him. he then came to Holy Prophet and said: what is your message? (what are your words), the Holy Prophet started to recite from the beginning of a short Surah and continued reading until ten to twelve verses of that Surah, then said to that man: these are my words, the man returned to the opponents and said to them, although I did not believe in him, whatever he recited for me was neither from any composition, nor was it from any literary works, nor was from poems or something; they were stable words which can never be denied, if you say these words are originated from sanity, it is a sheer lie, because sanity can never be the origin of such strong and stable words, if you say these words are poems, you are all into poetry and you know it better, and his words never resemble poems, if you say they are legends, such words are not legends and legends are big lies that people come up with,. In fact, the style of the holy Quran is the style of the holy Prophet's words and it was the very thing that Allah Almighty referred to as wisdom.
source : erfan.ir