A word frequently translated as the grave is the Hebrew שְׁא֣וֹל – sheol, but sheol is far more than just the grave. The grave is a portal into the underworld realm of the dead.
The Grave: שְׁא֣וֹל – sheol
Sides: בְּיַרְכְּתֵי – beyerekah
Once you enter the great gulf nothing can stop your fall into the core. The pit is everything below the mantle. If the sides of the pit is the lower mantle, then the pit includes the great gulf.
To cut off, destroy: קְצֵה – qatseh, qatsah, qatsu
The eyes of a fool are in the ends of the earth. This has a familiar ring to it. How about this for comparison? All his life has he looked away…
Extremity, extreme part, corner: כַּנְפ֥וֹת – kanaph
Heads are round but a beard can have corners. If you think this passage means that the Earth is flat and square, you also have to make the case that human heads are square. Good luck with that.
To cease, fail, have and end: אַפְסֵי – ephes
If my feet are at the end of my legs, then the coast is at the end of the land. The ends of the earth is simply where the land stops: it ceases, fails, has and end. The beach.
A Spellyng Mystaque
It turns out that theologians fudge their data just like scientists do. Sometimes things don't make sense, do they? What could possibly be wrong with helping them make sense? This approach is inductive, aka eisegesis.
Intermeddle with: יִתְגַּלָּֽע – yitgalla
To be obstinate, shew the teeth, then snarl, quarrel.
All wisdom: תּ֝וּשִׁיָּ֗ה – tushiyah
Sound, efficient wisdom, abiding success.
Separates: נִפְרָ֑ד – nifrad
To divide, disperse, divide, be out of joint, part, scatter abroad, separate self, sever self, stretch.
Seeks: יְבַקֵּ֣שׁ – yevakkesh
To seek, ask, beg, beseech, desire, enquire, get, make inquisition, procure, to search out (by any method, specifically in worship or prayer); by implication, to strive after.