Charles Spurgeon Commentary Luke 8:29

"For he was commanding the unclean spirit to come out from the man. For oftentimes it had seized him: and he was kept under guard, and bound with chains and fetters; and breaking the bands asunder, he was driven of the demon into the deserts." — Luke 8:29 (ASV)

Such cases have we often seen—young men who have been rescued from a course of vice, and who have been for a season helped towards virtue; but they have broken loose again. There was no holding them in; they had not learned self-restraint, and no one else could restrain them.