Revelation 9:1 ¶And the fifth angel sounded, and I saw a star fall from heaven unto the earth: and to him was given the key of the bottomless pit.
Revelation 9:2 And he opened the bottomless pit; and there arose a smoke out of the pit, as the smoke of a great furnace; and the sun and the air were darkened by reason of the smoke of the pit.
This gives the final beast great power.
Revelation 9:11 And they had a king over them, which is the angel of the bottomless pit, whose name in the Hebrew tongue is Abaddon, but in the Greek tongue hath his name Apollyon.
Jude 1:6 And the angels which kept not their first estate, but left their own habitation, he hath reserved in everlasting chains under darkness unto the judgment of the great day.
This finale beast, kills Gods two witnesses.
The final Roman govt. having the benefit of 6,000 years of history.Revelation 11:7 And when they shall have finished their testimony, the beast that ascendeth out of the bottomless pit shall make war against them, and shall overcome them, and kill them.
Revelation 17:8 The beast that thou sawest was, and is not; and shall ascend out of the bottomless pit, and go into perdition: and they that dwell on the earth shall wonder, whose names were not written in the book of life from the foundation of the world, when they behold the beast that was, and is not, and yet is.
The DEEP --same word G12 (abussos)
soundings--measurements you make to find out how deep water is.
The ancients dropped lines to measure depth. They could only reach so far.
Luke 8:27 And when he went forth to land, there met him out of the city a certain man, which had devils long time, and ware no clothes, neither abode in any house, but in the tombs.
28 When he saw Jesus, he cried out, and fell down before him, and with a loud voice said, What have I to do with thee, Jesus, thou Son of God most high? I beseech thee, torment me not.
29 (For he had commanded the unclean spirit to come out of the man. For oftentimes it had caught him: and he was kept bound with chains and in fetters; and he brake the bands, and was driven of the devil into the wilderness.)
30 And Jesus asked him, saying, What is thy name? And he said, Legion: because many devils were entered into him.
31 And they besought him that he would not command them to go out into the deep. G12 (abussos)
32 And there was there an herd of many swine feeding on the mountain: and they besought him that he would suffer them to enter into them. And he suffered them.
33 Then went the devils out of the man, and entered into the swine: and the herd ran violently down a steep place into the lake, and were choked.
Satan to be confined during the Millennium.
Revelation 20:1 ¶And I saw an angel come down from heaven, having the key of the bottomless pit and a great chain in his hand.
2 And he laid hold on the dragon, that old serpent, which is the Devil, and Satan, and bound him a thousand years,
3 And cast him into the bottomless pit, and shut him up, and set a seal upon him, that he should deceive the nations no more, till the thousand years should be fulfilled: and after that he must be loosed a little season. (Satan serves a purpose)
Jeremiah 31:34 And they shall teach no more every man his neighbour, and every man his brother, saying, Know the LORD: for they shall all know me, from the least of them unto the greatest of them, saith the LORD: for I will forgive their iniquity, and I will remember their sin no more.
Micah 7:19 He will turn again, he will have compassion upon us; he will subdue our iniquities; and thou wilt cast all their sins into the depths of the sea.
See also--Wikipedia---Deep sea