Mark 1:23

εὐθὺς : almost = ἰδοὺ, Matthew's word for introducing something important. αὐτῶν, in their synagogue, i.e., the synagogue of the same men who had been surprised at Christ's preaching. They are to get a new surprise, though one would have been enough for one day. We also get a surprise, for nothing in Mark's narrative thus far has prepared us to expect such an event as is reported. In his general sketch of the Galilean ministry (Mark 4:23-25) Matthew combines the three features: preaching, teaching, and healing. ἐν π. ἀ. = with an unclean spirit (Maldonatus, Holtz., H. C.), in the power of, possessed by, Meyer, Weiss, Keil, etc. An unclean spirit is Mark's standing name for what Matthew commonly calls δαίμων or δαιμόνιον.