َ كَلَّا لَوْ تَعْلَمُونَ عِلْمَ الْيَقِينِ ﴿۵﴾ لَتَرَوُنَّ الْجَحِيمَ ﴿۶﴾ ثُمَّ لَتَرَوُنَّهَا عَيْنَ الْيَقِينِ ﴿۷﴾ ثُمَّ لَتُسْأَلُنَّ يَوْمَئِذٍ عَنِ النَّعِيمِ ﴿۸﴾

﴾5﴿ Kalla law ta'lamoona 'ilmal yaqeen
﴾6﴿ Latara-wun nal jaheem
﴾7﴿ Thumma latara wunnaha 'ainal yaqeen
﴾8﴿ Thumma latus alunna yauma-izin 'anin na'eem

﴾5﴿ Indeed, if you have knowledge, it is the knowledge of religion
﴾6﴿ Indeed, you see Hell
﴾7﴿ Then indeed, you see it with the eye of certainty
﴾8﴿ Then indeed, on that Day, you will be asked about the blessings

[5] This is a warning.
‘Ilm al-Yaqīn (certain knowledge) is the type of knowledge through which a person reaches certainty about essentials in such a way that no doubt remains in those essentials.
This specific type of knowledge is connected to the heart, as the heart is the place of true certainty.
[6,7] This is a warning of the Hereafter.
“لَتَرَوُنَّ” is repeated, so the first refers to seeing from afar, and the second to seeing up close — or the first refers to seeing with the heart, and the second to seeing with the eyes.
“عَيْنَ الْيَقِينِ” is also called ‘ilm al-mushāhadah — meaning that the unseen and conceptual becomes as clearly witnessed as something seen with the eyes.
This level is higher than ‘ilm al-yaqīn (knowledge of certainty).
[8] This too is part of the warning of the Hereafter, and apparently, this address is general.
“النَّعِيمِ” — this is also general, because na‘īm is the plural of ni‘mah (blessing).
It includes safety, health, ease, hearing, sight, intellect, food and drink, cold water, shade, homes — and it is narrated from Mujāhid that every worldly pleasure is included in it.