[Jahannam]; that is: the intense burning; the one that meets those who enter it with utmost frowning and scowling.

And since their being specifically associated with it is not explicit in their punishment; he began to clarify this in his saying: [They will enter it]; that is: they will enter it; and they will directly experience its hardships. And since this implies the utmost dislike for it; and that there is no bedding for them other than its flames; the implication is: "So it will be a bedding for them; to surround them; so its burning will encompass them." This led to his saying: [So wretched is the bedding]; that is: the bedding is it; for the benefit of bedding is the comfort of the body; and this one melts the skin and flesh; then it returns immediately; whenever it melts, it returns; as a punishment for them; to show them what they used to deny regarding resurrection at all times, forever; just as they used to believe in that forever; as a recompense that is fitting; in contrast to what the people of Paradise have of comfort; and enjoyment; by the return of everything they cut from its fruits; and ate from its birds; because they believe in resurrection; so they attained this happiness.