Mark 1:21

And they went into Capernaum
Jesus and his four disciples he had just called, Simon and Andrew, James and John; though the Arabic and Persic versions read, "he went"; that is, Christ; and so Beza says it was read in a certain copy:

and straightway on the sabbath day he entered into the synagogue and
taught;
that is, immediately, as soon as he entered the, city, it being then sabbath day; or, as soon as the sabbath day came, he went to the synagogue at Capernaum, and his disciples with him; where the people used to meet weekly to hear the law read, and to be instructed in divine things; which opportunity Christ laid hold on to preach the Gospel to them, and teach them things concerning the kingdom of God.