Charles Spurgeon Commentary Mark 5:9

"And he asked him, What is thy name? And he saith unto him, My name is Legion; for we are many." — Mark 5:9 (ASV)

And he asked him, What is your name? And he answered, saying, My name is Legion: for we are many.

The devil is obliged to tell his name when Christ treats him like a catechized child, and he is compelled to crouch before Christ like a whipped cur at his master's feet.