Pray	Time

Tafseer Ibn Kathir of AL KAHFI [41]

أَوْ يُصْبِحَ مَاؤُهَا غَوْرًا فَلَن تَسْتَطِيعَ لَهُ طَلَبًا

Or its water will become sunken [into the earth], so you would never be able to seek it."