Quranic Challenge to the Jinn
Question

when the quran states that mankind and jinn cannot bring something like the Quran for even 3 verses, what is the explanation for Surah Jinn which quotes Jinn for 15 verses?
Praise be to Allah.The Quran is the Speech of Allah, spoken by Him with His letters and meanings, as He, the Exalted, said (translation of the meaning): {And if any one of the polytheists seeks your protection, then grant him protection so that he may hear the Words of Allāh [i.e., the Quran]. Then deliver him to his place of safety. That is because they are a people who do not know.} (At-Tawbah:6).
In the Quran, there are statements of various peoples that Allah, the Mighty and Majestic, has mentioned, including the believers like the prophets and the truthful, and the disbelievers, like Pharaoh and Qarun, and the hypocrites, as well as the angels, the jinn, the birds like the hoopoe, the ants, and others.
The purpose of mentioning these statements is to convey the meaning and not necessarily the exact wording. Sometimes the conveyed message is the exact wording, and sometimes it is the meaning, especially if it is impossible for it to be the exact wording, such as when the speaker is not speaking in Arabic. This has been explicitly stated by more than one of the scholars:
Zain Ad-Din Ar-Razi Al-Hanafi said in "Questions and Answers on the Oddities of the Verses of Revelation" (p. 144): "If it is asked: How did Allah, the Exalted, narrate here the speech of the sorcerers who believed and of Pharaoh (translation of the meaning): {They said, 'We believe in the Lord of the worlds'} to the saying of Allah: {And cause us to die as Muslims}, then narrated this meaning in Surah Taha and Surah Ash-Shu`ara with additions and omissions in the words attributed to them, when this event only occurred once, so how did their expression differ in it?
We say: The answer to this is that they spoke in their language, not in Arabic, and Allah, the Exalted, narrated that from them in Arabic several times, for a wisdom that necessitated repetition and reiteration, which we will explain in Surah Ash-Shu`ara, Allah willing. So, at one time He narrated it matching their wording in the translation, taking care of the wording, and after that, He narrated it by meaning, following the custom of the Arabs in varying speech and differing in their styles; so as not to bore if it was merely repetitive." End quote.
Shaykh al-Islam Ibn Taymiyah said in "At-Tis`iniyyah" (2/464): "Indeed, the letters and sounds that Moses heard were Hebrew, and those that Allah mentioned about him in the Quran were Arabic. If speech were merely letters and sounds, there would be no commonality at all between the speech that Moses heard and that which Allah mentioned that he heard. Thus, reporting that he heard these sounds, which he did not hear, would be a lie.
Likewise, all those whom Allah narrated in the Quran that they spoke from the previous nations who spoke languages other than Arabic, they spoke in their languages, and Allah narrated that in the language in which the Quran was revealed, which is Arabic. And the Speech of Allah is truth. If their speech was just letters and sounds, and the letters and sounds they said are not like these, then it would not be possible to narrate from them at all. Rather, their speech was letters and meanings, so Allah narrated that from them in another language, and the letters follow the meanings, and the meanings are the main intended purpose, as the speech of all creatures is translated." End quote.
At-Tahir said: "The meaning of the statement here is: to convey their intention to those they want to reach among their kind, in the manner in which they understand each other," At-Tahrir wat-Tanwir (29/220).
And he said: "This is narrated from the speech of the jinn," At-Tahrir wat-Tanwir (29/222).
In summary, what this ignorant objector mentioned only demonstrates his ignorance, narrow-mindedness, and poor understanding.
If Allah's narration of the speech of the jinn or humans, whether believers or disbelievers, in His Book, meant that those whom Allah narrated from them said "Quran," then that would mean that all these humans, and the jinn, had brought forth a Quran from themselves, and then Allah transmitted this Quran in "His Quran"; then He challenged them to produce something like it.
This could not be from the weakest of people in intellect; rather, it is only imagined and found problematic by someone who is ignorant, who does not know the places of argument, and the aspects of speech.
And it is astonishing that anyone would believe such nonsense, be disturbed by it, and think there is a real problem!!
And Allah knows best.