Commentaries:
The great archangel who later became Satan and his legions of angels were once clean spirits until they rebelled against the Most High God. In the ages before human history, they dwelled in the preincarnate Christ's presence, and thus they are very aware of His attributes. Thus, the demon in the synagogue does not hesitate to acknowledge "the Holy One of God."
Jesus does not let it speak of Him because He would not receive testimony from such a lying, diabolical source. For the same reason, Paul refuses the public witness of a fortune-telling spirit in Philippi (Acts 16:16-18). There can be no association between Christ and Satan. Jesus does not even carry on conversations with demons, but He commands and instructs them by the power and authority of His heavenly Father (Matthew 8:31-32; Mark 1:34).
Martin G. Collins
The Miracles of Jesus Christ: Exorcism in the Synagogue
Other Forerunner Commentary entries containing Mark 1:24:
Mark 8:22-26