Al-Mukhtasar
ثُمَّ بَعَثْنَـٰهُمْ لِنَعْلَمَ أَىُّ ٱلْحِزْبَيْنِ أَحْصَىٰ لِمَا لَبِثُوٓا۟ أَمَدًا ﴿١٢﴾
Then after their lengthy sleep I woke them up to demonstrate which of the two groups disputing their duration of stay in the cave knows this duration best.