For great is thy mercy toward me: and thou hast delivered my soul from the lowest hell.(Psalms 86:13) KJV
The ancient Hebrews had a well developed idea of life after death. For them death, the grave, was a portal into a complex underworld realm. The grave is just the beginning of what happens next.
It just happens that the way that the ancient Hebrews described hell aligned with the zones of the interior of the Earth that we can infer from seismological data: crust, mantle, great gulf and core.
Levels of Hell
The Levels of Hell
|Earth (erets)||World (tebel)|
|bad sheol||erets beriach|
mayim tachath erets