Luke 8:26-39
“Notice what you notice.” Luke’s account of the Gerasene demoniac… Here are Luke’s verses 28 and 29: When he saw Jesus, he cried out and fell down before him and said with a loud voice, “What have you to do with me, Jesus, Son of the Most High God? I beg you, do not torment me.” For He had commanded the unclean spirit to come out of the man. So the demons are asking not to be tormented. Presumably the “torment” was Jesus simply commanding them to come out of the man. Then the demons requested that they be cast into the pigs. Put all that together – the demons “requested” a body to inhabit and did not want to be cast into the abyss, also translated as the “bottomless pit”.
An online source helps me to understand all that. “The Abyss is a place for evil spirits and a place of eternal judgment. James 2:19 declares that even the demons believe that there is only ‘one God,’ however the demons ‘shudder’ because they are aware of the judgment of God that they (demons) will suffer eternal punishment. Matthew 25:41 describes eternal punishment (the Abyss) as an ‘eternal fire.’ That would be a place of great torment that caused a person, angel, or demon to ‘shudder’. (https://www.allaboutjesuschrist.org/jesus-casts-out-demons-and-turns-them-to-pigs-faq.htm) So presumably if the demons did not have somewhere else to go, they would be condemned for all eternity. All that makes more sense now!
Blessings!