A.T. Robertson Commentary Luke 8:28

"And 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 the Most High God? I beseech thee, torment me not." — Luke 8:28 (ASV)

Fell down (προσεπεσεν). Second aorist active of προσπιπτω, to fall forward, towards, prostrate before one as here. Common verb. Mr 5:6 has προσεκυνησεν (worshipped).

The Most High God (του θεου του υψιστου). Uncertain whether του θεου genuine or not. But "the Most High" clearly means God as already seen (Luke 1:32,35,36; 6:35). The phrase is common among heathen (Numbers 24:16; Micah 6:6; Isaiah 14:14). The demoniac may have been a Gentile, but it is the demon here speaking. See on Mr 2:7; Matthew 8:29 for the Greek idiom (τ εμο κα σο). "What have I to do with thee?" See there also for "Torment me not."