'Unclean' in the Bible

In the synagogue there was a man with an unclean demonic spirit who cried out with a loud voice,

Amazement came over them all, and they kept saying to one another, “What is this message? For He commands the unclean spirits with authority and power, and they come out!”

They came to hear Him and to be healed of their diseases; and those tormented by unclean spirits were made well.

For He had commanded the unclean spirit to come out of the man. Many times it had seized him, and though he was guarded, bound by chains and shackles, he would snap the restraints and be driven by the demon into deserted places.

As the boy was still approaching, the demon knocked him down and threw him into severe convulsions. But Jesus rebuked the unclean spirit, cured the boy, and gave him back to his father.

“When an unclean spirit comes out of a man, it roams through waterless places looking for rest, and not finding rest, it then says, ‘I’ll go back to my house where I came from.’