These questions expect negative answers. They can be expressed as statements. Alternate translation: "You have not gone to the sources of the waters of the sea, or walked in the lowest parts of the deep. The gates of death have not been revealed to you, and you have not seen the gates of the shadow of death. You do not understand the earth in its expanse." (See: [[rc://en/ta/man/translate/figs-rquestion]])
This refers to the sea or ocean where the water is very deep. Alternate translation: "the deep sea" or "the ocean depths" or "the deep water" (See: [[rc://en/ta/man/translate/figs-nominaladj]])