The Holy Quran 18:12 — Surah Al-Kahf

Arabic text

ثُمَّ بَعَثْنَـٰهُمْ لِنَعْلَمَ أَىُّ ٱلْحِزْبَيْنِ أَحْصَىٰ لِمَا لَبِثُوٓا۟ أَمَدًا

Translation

Thereafter (after 309 years) We raised them (from their sleep) so that We may know which of the two groups will be able to specify (remember) correctly for how long they had remained (asleep in the cave). (When they awoke, some of them said that they had slept for a day or a part of a day while others said that Allaah knew best how long they remained asleep. It was the second group that held the correct opinion.)

Tafsir (excerpt) — Tafsir Usmani

The duration of the sleep of the People of the Cave: after many years Almighty Allah awakened them, so that it might become clear which of those who disagreed had the more accurate estimate of the length of their sleep.

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