“ties up.” The Greek word translated “ties up” is the common word deō (#1210 δέω), which means to bind or tie up. However, here it has a special meaning. The word was used in magic and spells for binding someone via a spell. The word was used “to describe the ‘binding’ power of curses.”a The context is the casting out of demons (v. 28), so the “binding” in this verse refers to binding a demon and making it powerless by the power of God.