John Gill Commentary Isaiah 14:15

"Yet thou shalt be brought down to Sheol, to the uttermost parts of the pit." — Isaiah 14:15 (ASV)

Yet thou shalt be brought down to hell Into a very low and miserable condition; see (Matthew 11:23) instead of ascending to heaven: or "to the grave"; though, inasmuch as afterwards a burial is denied him, the word may be taken for the infernal pit, and so is, as much as can be, opposed to heaven; and this will be true of antichrist, when the beast and false prophet will be cast alive into the lake of fire, (Revelation 19:20).

to the sides of the pit ; instead of being on the mount of the congregation in the sides of the north; another word for hell, the pit of corruption, and the bottomless pit. The Targum is, "to the ends of the lake of the house of perdition;" the place of everlasting destruction.