For he had commanded the unclean spirit to come out of the man. (For many a time it had seized him. He was kept under guard and bound with chains and shackles, but he would break the bonds and be driven by the demon into the desert.)
Christ ordered His disciples to sea that He might display His glory upon the water and work kindness for a possessed man on the far shore. They that have Christ accompanying them may safely venture anywhere; but even at His word, in a calm, they must prepare for storm and utmost peril. The devil, prince of the power of the air, perhaps suspected Christ's purpose to cast out that legion and poured tempest upon the ship to prevent it.
AI summary
Commenting on Luke 8:22-39
And Jesus asked him, saying, what is thy name?.... This question was put, not out of ignorance in Christ, but for the sake of those that were with him; and partly, that the miserable condition of this man might be the more known; and partly, that his own power might be the more manifest in the dispossession: and he said, legion, because many devils were...
(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.) (k) By force and violence, as a horse when he is spurred.