ذَلِكَ جَزَاء أَعْدَاء اللَّهِ النَّارُ لَهُمْ فِيهَا دَارُ الْخُلْدِ جَزَاء بِمَا كَانُوا بِآيَاتِنَا يَجْحَدُونَ ﴿٢٨﴾

وَقَالَ الَّذِينَ كَفَرُوا رَبَّنَا أَرِنَا الَّذَيْنِ أَضَلَّانَا مِنَ الْجِنِّ وَالْإِنسِ نَجْعَلْهُمَا تَحْتَ أَقْدَامِنَا لِيَكُونَا مِنَ الْأَسْفَلِينَ ﴿٢٩﴾

That is the recompense of the enemies of Allah: the Fire. Therein will be for them the eternal home, a recompense for that they used to deny Our Ayat.

And those who disbelieve will say: "Our Lord! Show us those among Jinn and men who led us astray, that we may crush them under our feet so that they become the lowest.''

It was reported that Ali, may Allah be pleased with him, said, concerning the phrase, الَّذَيْنِ أَضَلَّانَا (those who led us astray):

"Iblis and the son of Adam who killed his brother.''

As-Suddi reported that Ali, may Allah be pleased with him, said;

"Iblis is followed by everyone who commits Shirk and the son of Adam is followed by everyone who commits a major sin. So Iblis is the one who calls people to every evil thing, such as Shirk and lesser sins.''

As for the first son of Adam, it is as confirmed in the Hadith:

مَا قُتِلَتْ نَفْسٌ ظُلْمًا إِلَّا كَانَ عَلَى ابْنِ آدَمَ الْأَوَّلِ كِفْلٌ مِنْ دَمِهَا،لِأَنَّهُ أَوَّلُ مَنْ سَنَّ الْقَتْل

No soul is wrongfully killed, but a share of the burden (of that sin) will be upon the first son of Adam, because he was the first one who set the precedent of killing another.

...نَجْعَلْهُمَا تَحْتَ أَقْدَامِنَا ...

that we may crush them under our feet,

means, `make them beneath us in the torment, so that they will be punished more severely than us.'

... لِيَكُونَا مِنَ الْأَسْفَلِينَ

so that they become the lowest.

means, in the lowest level of Hell, as already mentioned in Surah Al-A`raf, where the followers ask Allah to multiply the torment for their leaders:

قَالَ لِكُلٍّ ضِعْفٌ وَلَـكِن لاَّ تَعْلَمُونَ

(Allah) said: "For each one there is double (torment), but you know not.'' (7:38)

i.e., Allah will give each of them the torment and punishment they deserve for their deeds.

This is like the Ayah:

الَّذِينَ كَفَرُواْ وَصَدُّواْ عَن سَبِيلِ اللَّهِ زِدْنَـهُمْ عَذَابًا فَوْقَ الْعَذَابِ بِمَا كَانُواْ يُفْسِدُونَ

Those who disbelieved and hinder (men) from the path of Allah, for them We will add torment to the torment because they used to spread corruption. (16:88)