وَاسْتَفْتَحُوا وَخَابَ كُلُّ جَبَّارٍ عَنِيدٍ ﴿۱۵﴾ مِنْ وَرَائِهِ جَهَنَّمُ وَيُسْقَى مِنْ مَاءٍ صَدِيدٍ ﴿۱۶﴾ يَتَجَرَّعُهُ وَلَا يَكَادُ يُسِيغُهُ وَيَأْتِيهِ الْمَوْتُ مِنْ كُلِّ مَكَانٍ وَمَا هُوَ بِمَيِّتٍ وَمِنْ وَرَائِهِ عَذَابٌ غَلِيظٌ ﴿۱۷﴾ مَثَلُ الَّذِينَ كَفَرُوا بِرَبِّهِمْ أَعْمَالُهُمْ كَرَمَادٍ اشْتَدَّتْ بِهِ الرِّيحُ فِي يَوْمٍ عَاصِفٍ لَا يَقْدِرُونَ مِمَّا كَسَبُوا عَلَى شَيْءٍ ذَلِكَ هُوَ الضَّلَالُ الْبَعِيدُ ﴿۱۸﴾

﴾15﴿ Wastaftahoo wa khaaba kullu jabbaarin 'aneed
﴾16﴿ Minw waraaa'ihee jahannamu wa yusqaa min maaa'in sadeed
﴾17﴿ Yatajarra'uhoo wa laa yakaadu yuseeghuhoo wa ya'teehil mawtu min kulli makaaninw wa maa huwa bimaiyitinw wa minw waraaa'ihee 'azaabun ghaleez
﴾18﴿ Masalul lazeena kafaroo bi Rabbihim; a'maaluhum karamaadinish taddat bihir reehu fee yawmin 'aasifin; laa yaqdiroona mimmaa kasaboo 'alaa shai'; zaalika huwad dalaalul ba'eed

﴾15﴿ And he sought to settle the matter but was disappointed; every rebellious opponent
﴾16﴿ Before him is Hell, and he will be given to drink water that is a mixture of blood and pus
﴾17﴿ He drinks it sip by sip but cannot swallow it easily, and death comes to him from every side, yet he does not die, and ahead of him is a severe torment
﴾18﴿ The example of those who disbelieved in their Lord is that their deeds are like ashes blown away by a strong wind on a stormy day. They have no power over anything they have earned. That is the farthest limit of misguidance

[15] In this verse, there is a warning directed at the deniers. (وَاسْتَفْتَحُوا)—this means that the prophets sought help from Allah the Exalted, or it could mean that the disbelievers requested a decisive judgment from Allah, as seen in verse 19 of Surah Al-Anfal.
(جَبَّارٍ) refers to someone who does not acknowledge anyone else's right over himself.
(عَنِيدٍ) refers to someone who turns away from the truth out of stubborn opposition.
(وَخَابَ)—this points to the outcome of استفتحوا, meaning the side of falsehood was disappointed and doomed as a result of that plea.
[16,17] In these two verses, there is a detailed warning about the Hereafter for the deniers, described in six ways:
(مِنْ وَرَائِهِ)—this word can mean both "behind" and "ahead," depending on the context. Here, it means ahead, i.e., after the punishment of this world and the grave, there is the punishment of the Hereafter.
(يَتَجَرَّعُهُ)—this refers to the person trying to swallow it because of its extreme heat and foulness.
(وَيَأْتِيهِ الْمَوْتُ)—this can mean either the causes of death, such as the various forms of painful punishment coming from every direction, or it can refer to death as sorrow and grief. A similar meaning appears in verse 36 of Surah Fatir.
Note: This is evidence that the people of Hell will not be annihilated.
(وَمِنْ وَرَائِهِ عَذَابٌ غَلِيظٌ)—this means that this punishment is a drink, and in addition to it, there are foods like Dari‘ (bitter thorn), Ghislin (pus and filth), Zaqqum (a tree in Hell), and other punishments.
[18] Since in the previous verse the punishment of the disbelievers was mentioned, an objection could arise: “But they have done good deeds.” So, in this verse, the answer is hinted at by giving a parable to illustrate the destruction of those deeds.
The essence of the parable is this: just as a strong wind blows over a heap of ashes all day long, scattering it into the air until nothing remains—likewise, the deeds of the polytheists will be rendered useless on the Day of Judgment. Despite appearing good outwardly, those deeds will carry no weight due to their disbelief and shirk.
The comparison is made to (كَرَمَادٍ) (ashes) because ashes have no benefit—just as the deeds of a polytheist are worthless.
Also, (رَمَادٍ) is what remains after something like wood has been burned—symbolizing that these deeds are already "burned" and lifeless after being done, due to the corruption of faith. So, (أَعْمَالُهُمْ) refers to actions that appeared righteous on the outside.
(لَا يَقْدِرُونَ)—the pronoun here refers either to the disbelievers or to the people of the ashes; however, the first opinion (referring to the disbelievers) is the preferred one.