لَتَرَوُنَّ ٱلْجَحِيمَ
Latara-wun nal jaheem
you will surely see jahim,
This line sits at the turn of the surah's certainty vocabulary: knowledge of certainty is named just before it, eye of certainty just after, and the seeing itself falls between the two. Later writers built a three-stage scheme from those phrases and a third, truth of certainty, which the Qur'an places elsewhere and never here. Jahim is kept as one of the fire's own names, used of a blaze at full strength.