A.T. Robertson Commentary Luke 8:31

"And they entreated him that he would not command them to depart into the abyss." — Luke 8:31 (ASV)

Into the abyss (εις την αβυσσον). Rare old word common in LXX from α privative and βαθυς (deep). So bottomless place (supply χωρα). The deep sea in Ge 1:2; 7:11. The common receptacle of the dead in Ro 10:7 and especially the abode of demons as here and Re 9:1-11; 11:7; 17:8; 20:1,3.