النساۤء — An-Nisa' Ayat 18
وَلَيْسَتِ التَّوْبَةُ لِلَّذِيْنَ يَعْمَلُوْنَ السَّيِّاٰتِۚ حَتّٰىٓ اِذَا حَضَرَ اَحَدَهُمُ الْمَوْتُ قَالَ اِنِّيْ تُبْتُ الْـٰٔنَ وَلَا الَّذِيْنَ يَمُوْتُوْنَ وَهُمْ كُفَّارٌ ۗ اُولٰۤىِٕكَ اَعْتَدْنَا لَهُمْ عَذَابًا اَلِيْمًا
Wa laisatit-taubatu lil-lażīna ya‘malūnas-sayyi'āt(i), ḥattā iżā ḥaḍara aḥadahumul-mautu qāla innī tubtul-āna wa lal-lażīna yamūtūna wa hum kuffār(un), ulā'ika a‘tadnā lahum ‘ażāban alīmā(n).
"But repentance is not [accepted] of those who [continue to] do evil deeds up until, when death comes to one of them, he says, "Indeed, I have repented now," or of those who die while they are disbelievers. For them We have prepared a painful punishment."