Tafsir of Al-Mulk 67:7

When they are cast into it: That is, thrown into it just as firewood is thrown into a great fire.

They hear for it a: That is, for Hell itself, as is apparent, and it is supported by what follows. The prepositional phrase is connected to a suppressed state [hal] qualifying His saying: "a rumbling" [shaheeqan]; because it was originally its description, and when it was placed forward, it became a state. That is: They hear it while it is emitting a "rumbling"—meaning a sound like the braying of donkeys—which is its repulsive and horrific crackling. In this, there is an explicit metaphor [isti'arah tasrihiyyah].

It is permitted that the "rumbling" belongs to its inhabitants—those who were cast into it before, or from among themselves—as in His saying: "For them therein is wailing and sighing [zafeer wa shaheeq]." In this case, the discourse involves the omission of a genitive attribute, or a figurative attribution. This has been objected to on the grounds that this only occurs for them after they are settled in the Fire and after it is said to them: "Begone into it!" which occurs six thousand years after their entry, according to some traditions. This has been refuted by the argument that this only proves their state is restricted to wailing and sighing at that time, not that such sounds do not occur from them beforehand.