mark 1:21 And they went into Capernaum; and straightway on the sabbath day he entered into the synagogue, and taught. - Free Bible Online

      Mr 1:21-39. HEALING OF A DEMONIAC IN THE SYNAGOGUE OF CAPERNAUM AND THEREAFTER OF SIMON'S MOTHER-IN-LAW AND MANY OTHERS--JESUS, NEXT DAY, IS FOUND IN A SOLITARY PLACE AT MORNING PRAYERS, AND IS ENTREATED TO RETURN, BUT DECLINES, AND GOES FORTH ON HIS FIRST MISSIONARY CIRCUIT. ( = Lu 4:31-44; Mt 8:14-17; 4:23-25).

      21. And they went into Capernaum--(See on Mt 4:13).
      and straightway on the sabbath day he entered into the synagogue, and taught--This should have been rendered, "straightway on the sabbaths He entered into the synagogue and taught," or "continued to teach." The meaning is, that as He began this practice on the very first sabbath after coming to settle at Capernaum, so He continued it regularly thereafter.

JFB.