Surah Al-Jinn, Ayah 9

The Jinns stealing Information from the Sky before the the Messenger ﷺ was sent and striking Them with flaming Fire after His Coming.

Allah informs about the Jinns when He sent His Messenger Muhammad ﷺ and revealed the Qur'an to him. Among the ways He protected it (the Qur'an) was by filling sky with stern guards guarding it from all of its sides. The devils were then expelled from the places where they used to sit prior to that. This was so that they could not steal anything from the Qur'an and tell it to the soothsayers, thereby causing matters to be confused and mixed up. If this happened it would not be known who was being truthful. Allah did this out of His kindness to His creation, His mercy upon His servants and His protection of His Mighty Book (the Qur'an). This is why the Jinns said,

وَأَنَّا لَمَسْنَا السَّمَاءَ فَوَجَدْنَاهَا مُلِئَتْ حَرَ‌سًا شَدِيدًا وَشُهُبًا (...and that we sought [ to reach ] the sky, but we found it filled with stern guards and flames....72:8). The word sama' is used in two different senses: 'sky' as well as 'cloud'. It would appear that here the word is used in the latter sense.

The Jinn Used to Go only up to the Clouds to Eavesdrop, Not to the Sky

The Jinn and the devils used to go up to the sky means that they used to go to the 'clouds', take up positions there to sit and eavesdrop. The proof of this is found in Sahih of Bukhari on the authority of Sayyidah ` A'ishah ؓ عنہا who reports:

In this world, in addition to human beings and angels, there is another set of creatures known as jinn. Human beings cannot see them but, in the Quran, they have been mentioned at several places. These verses show that among the jinn also there are guided and misguided types. Just as there are foolish leaders who misguide the common people, similarly there are foolish leaders among the jinn, who go on misguiding them with deceitful utterances. So far as the angels are concerned, they are not being put to the test, and thus do not have free will. They simply follow the commands given by God.