John Calvin Commentary Luke 4:33

"And in the synagogue there was a man, that had a spirit of an unclean demon; and he cried out with a loud voice," — Luke 4:33 (ASV)

A man having a spirit of an unclean devil. This mode of expression, which Luke employs, conveys the idea that the man was driven by the impulse of the devil. By the permission of God, Satan had seized the faculties of his soul in such a manner as to drive him not only to speak, but to perform other movements, at his pleasure. And thus, when the demoniacs speak, the devils, who have received permission to tyrannize, speak in them and by them.

The title, Holy One of God, was probably taken from a manner of speaking that was, at that time, in ordinary and general use. The Messiah was so called because he was to be distinguished and separated from all others, as endowed with eminent grace, and as the Head of the whole Church.