2:23 And if you are in doubt as to what We have sent down to Our servant, then bring a chapter like this, and call upon your witnesses other than God if you are truthful.
2:24 And if you cannot do this; and you will not be able to do this; then beware the Fire WHOSE FUEL IS PEOPLE AND STONES, it has been prepared for the rejecters.
66:6 O you who believe, protect yourselves and your families from a Fire whose FUEL IS PEOPLE AND STONES. Guarding it are stern and powerful angels who do not disobey God in what He commanded them; and they carry out what they are commanded to.
Stones mentioned in this verse 2:24 & 66:6 refer to the idols which the polytheists worshipped.
21:98 Both you and what you serve besides God shall be FUEL OF HELL; you will enter it.
21:99 If these had been Gods, then they would not have entered it! And all will abide therein.
21:100 They will be breathing heavily in it, and they will not be heard therein.
29:25 And he (Abraham) said: “You have taken idols besides God in order to preserve some friendship among you in this worldly life. But then, on the Day of Resurrection, you will reject one another, and curse one another. YOUR DESTINY IS HELL, and you will have no victors.”