I noticed a new layer of detail today as I studied these words -- King Benjamin is also quoting Jacob, Brother of Nephi.
Compare Jacob's words:
10 And according to the power of , for justice cannot be denied, ye must go away into that of fire and brimstone, whose flames are unquenchable, and whose smoke ascendeth up forever and ever, which lake of fire and brimstone is . (Jacob 6)
...with the words of King Benjamin:
25 And if they be evil they are consigned to an awful of their own guilt and abominations, which doth cause them to shrink from the presence of the Lord into a state of and torment, from whence they can no more return; therefore they have drunk damnation to their own souls.
26 Therefore, they have drunk out of the of the wrath of God, which justice could no more deny unto them than it could deny that should fall because of his partaking of the forbidden ; therefore, could have claim on them no more forever.
27 And their is as a of fire and brimstone, whose flames are unquenchable, and whose smoke ascendeth up and ever. (Mosiah 3)