Firstly: Rhetoric of Quran.
Generally, speech can’t be rhetorical unless it has the quality of meaning and the beauty of pronunciation. According to Arab that time, who were known of eloquence and rhetoric, Quran was a big challenge especially was recited by an illiterate person who couldn’t even read to prove that this Qur’an isn’t Mohammad composition, but it’s speaking of Allah.
Allah says in Surah Az-Zumar verse 28 “An Arabic Qur’ân, without any crookedness (therein) in order that they may avoid all evil which Allâh has ordered them to avoid, fear Him and keep their duty to Him.”
“Say: “If the mankind and the jinn were together to produce the like of this Qur’ân, they could not produce the like thereof, even if they helped one another.” {Al-Israa. Verse 88}.
In another hand, the reader of Qur’an clearly notices accuracy of words and vocabularies that do precise meaning can’t be replaced by other words. For example, it is mentioned in Yusuf Surah the word “shara” and the word “aishtara”.. In the first look, as Arabic reader, the reader will understand them like they have the same meaning. By contrast, they are opposite; the first one have meaning of the word “sold”, but the other one means “bought”. Allah said “And they sold him for a reduced price – a few dirhams – and they were, concerning him, of those content with little.” The previous verse in Arabic” {Yusuf Surah. Verse 20} “وَشَرَوۡهُ بِثَمَنِۭ بَخۡسٖ دَرَٰهِمَ مَعۡدُودَةٖ وَكَانُواْ فِيهِ مِنَ الزاهدينَ”
“وَقَالَ ٱلَّذِي ٱشۡتَرَىٰهُ مِن مِّصۡرَ لِٱمۡرَأَتِهِۦٓ أَكۡرِمِي مَثۡوَىٰهُ” in English “And the one from Egypt [590] who bought him said to his wife, “Make his residence comfortable” {Yusuf Surah. Verse 21}
In these verses, no one can replace both words, because there will be a big misunderstanding, and the meaning is going to be incorrect.
Another example, Allah said in {Al-Maeda. Verse 6}: “O you who believe! When you intend to offer As-Salât (the prayer), wash your faces and your hands (forearms) up to the elbows, rub (by passing wet hands over) your heads” in Arabic Qur’an: “يَـٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوٓاْ إِذَا قُمۡتُمۡ إِلَى ٱلصَّلَوٰةِ فَٱغۡسِلُواْ وُجُوهَكُمۡ وَأَيۡدِيَكُمۡ إِلَى ٱلۡمَرَافِقِ وَٱمۡسَحُواْ بِرُءُوسِكُمۡ”.. In the final word برؤوسكم the word is joined with the letter “ب” which let the reader think why that letter was put although the verb rub “امسحوا” is a transitive verb; it should have followed by just an object not a proposition. The wisdom becomes clear, that in the ablution “wadu “ Muslim have to rub some of his head, so the letter “ب ‘’means some not all the head.
In addition, there is the beauty of similes and metaphors in Qur’an which let the reader fell deeply in wonderful imagination. For instance, Allah the Almighty uses an amazing description of his majesty in An Noor Surah “Allah is the Light of the heavens and the earth. The example of His light is like a niche within which is a lamp, the lamp is within glass, the glass as if it were a pearly [white] star lit from [the oil of] a blessed olive tree, neither of the east nor of the west, whose oil would almost glow even if untouched by fire. Light upon light. Allah guides to His light whom He wills. And Allah presents examples for the people, and Allah is knowing of all things.” {Verse 35}.
Another example, Allah describes deeds of the disbelieved people like a mirage in lowland, so the reader can understand by this great simile that their deeds are nothing and with no reward.
“But those who disbelieved – their deeds are like a mirage in a lowland which a thirsty one thinks is water until, when he comes to it, he finds it is nothing but finds Allah before Him, and He will pay him in full his due; and Allah is swift in account”. {An Noor Surah. Verse 39}
In addition anyone can notice the marvelous metaphor in this Ayah (Verse) “And do not spy or backbite each other. Would one of you like to eat the flesh of his brother when dead? You would detest it. And fear Allah; indeed, Allah is Accepting of repentance and Merciful.”
The metaphor here means if the man talks any bad thing about someone, he will be like he himself eats flesh of the same one he spies.
