A.T. Robertson Commentary Luke 11:15

"But some of them said, By Beelzebub the prince of the demons casteth he out demons." — Luke 11:15 (ASV)

Dumb (κωφον). See on Mt 9:32.

By Beelzebub (εν Βεεζεβουλ). Blasphemous accusation here in Judea as in Galilee (Matthew 12:24,27). See on Matthew for discussion of the form of this name and the various items in the sin against the Holy Spirit involved in the charge. It was useless to deny the fact of the miracles. So they were explained as wrought by Satan himself, a most absurd explanation.