An-Naba: (21) Indeed, Hell has been a place of ambush...

"Indeed, Hell has been a place of ambush." This initiates the detailed elaboration regarding the rulings of the Day of Judgment, following the description of its terror.

Mirṣād is a noun of place, similar to midmār (a racetrack), referring to the location where horses are prepared for racing. The form mifʿāl functions in this manner, as explicitly stated by al-Rāghib, al-Jawharī, and others, just as it also functions as a noun of instrument or an intensive adjective (ṣifah mushabbahah).

The apparent meaning is that it is a place of observation and surveillance, where the keepers of the Fire lie in wait to punish the disbelievers. It has been said that the keepers of Paradise lie in wait there to protect the believers from its heat as they cross over it. It has also been said that the angels—peace be upon them—lie in wait for both groups: to punish one (the disbelievers) and to guard the other (the believers).

It is permissible for it to be an intensive form (ṣīghat mubālaghah), like miḥāriṣ (one who is diligent/frequent in guarding), meaning that it is intensely vigilant in observing the disbelievers so that not one of them escapes, or intensely vigilant in observing the believers so that none of them are harmed by its heat, or intensely vigilant in observing both groups in the manner previously mentioned. Attributing this [vigilance] to Hell is either a metaphor or a simile.

It is stated in al-Baḥr that mirṣād carries the meaning of relation, i.e., "possessing observation" (dhāt raṣd). Al-Mirṣād may also be interpreted as "the path" in an absolute sense, which is one of its meanings, and thus it applies to both groups. Hence, al-Hasan said—as narrated from him by Ibn Jarīr, Ibn al-Mundhir, and ‘Abd ibn Ḥumayd—regarding the verse: "No one shall enter Paradise until he crosses over the Fire." Qatādah also said—as narrated by the same scholars—"Know that there is no path to Paradise until you traverse the Fire." And [this leads to] the Exalted’s saying...