Quran 18:2 — The Cave (Al-Kahf)

قَيِّمًا لِيُنذِرَ بَأسًا شَديدًا مِن لَدُنهُ وَيُبَشِّرَ المُؤمِنينَ الَّذينَ يَعمَلونَ الصّٰلِحٰتِ أَنَّ لَهُم أَجرًا حَسَنًا

A perfect (scripture) to warn of severe retribution from Him, and to deliver good news to the believers who lead a righteous life, that they have earned a generous recompense.

[18:1] Praise GOD, who revealed to His servant this scripture, and made it flawless.

[18:3] Wherein they abide forever.