Is Quranic language have any similarity with soothsayers?

I'm new to this website, so I'm not sure if this question can be asked here but this thing is bothering me. I don’t speak in arabic but I have heard from my childhood that Quran is different from all pre islamic literature and it's unique and standout on It's own.But I come across a anti islamic site which have this quote from some book(I don’t remember reference but I have copied this quote from there)"The Qur'an is written throughout in rhyming prose (saj'), and appears therefore, to a greater or lesser extent, artistically constructed and strongly rhetorical in comparison with ordinary prose. The individual parts of a sentence, the sentence or combination of sentences which end with a rhyme and are called verses (ayah, plural ayat) follow the rhyme scheme a-a, b-b, c-c. The same rhyme is repeated not only once but as often as the author pleases, e.g. a-a-a, b-b, c-c-c-c (surah ci). Short surahs sometimes have only one rhyme. Ideally, as in the earliest surahs, the rhymes follow in rapid succession at farily equal intervals; this also seems to have been the case with the rhymes of the ancient Arabic soothsayers. (Presumably the Prophet in fact adopted the alternation of short rhyme sequences from the practice of these soothsayers ...). In the surahs from the latter years of Muhammad's career the verses lengthen increasingly, and the rhymes no longer have the effect of rhetorically enlivening elements, but sound monotonous and often forced, as though they have been added later. On page 198, we are told: A large number of early pronouncements in the Qur'an are introduced by strange oaths, or rather asseverations, a stylistic device which Muhammad in all probability copied from the old Arabic soothsayers."Can u please refute this? I have always believed that quran is individual and its not possible for anyone to write like Quran but they are accusing Muhammad copied literacy style from old arabic soothsayers.