Sea

Bismillahir Rahmaanir Raheem

Allah  Ta'ala says in the Qur'aan Sharief:

 "Or (the unbelievers' state) is like the darkness in a deep sea. It is covered by waves, above which are waves, above which are clouds. Darkness, one above another. If a man stretches out his hand, he cannot see it..." 
[Surah An-Noor 24:40]