After Allah mentioned that the people of Paradise will address the people of the Fire, He stated that there is a barrier between Paradise and the Fire, which prevents the people of the Fire from reaching Paradise. Ibn Jarir said, "It is the wall that Allah described,
(So a wall will be put up between them, with a gate therein. Inside it will be mercy, and outside it will be torment.) 57:13 It is also about Al-A`raf that Allah said,
وَعَلَى الاٌّعْرَافِ رِجَالٌ
(and on Al-A`raf will be men)." Ibn Jarir recorded that As-Suddi said about Allah's statement,
Stated next is the status of the people of A` raf that they have yet to enter Paradise, though they hope to. After that it is said: وَإِذَا صُرِفَتْ أَبْصَارُهُمْ تِلْقَاءَ أَصْحَابِ النَّارِ قَالُوا رَبَّنَا لَا تَجْعَلْنَا مَعَ الْقَوْمِ الظَّالِمِينَ ﴿47﴾ (And when their eyes will be turned towards the people of the Fire, they will say, "Our Lord, do not put us in the company of the unjust people - 47).
Tazkirul Quran
Maulana Wahiduddin Khan
It happens in the world that believers and those who deny the truth alike are recipients of both the bounties and the afflictions sent down by God. But, it will not be so in the Hereafter. There, a barrier will be set up between the two. There, the joys of the bounties savoured by the people of Paradise will not reach the people of Hell, and similarly the woes afflicting the people of Hell will not reach the people of Heaven.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.