MARK 1.21-22: And they went into Capernaum, and immediately on the Sabbath he entered the synagogue and was teaching. (22) And they were astonished at his teaching, for he taught them as one who had authority, and not as the scribes. (ESV)
The town of Caperaum in the region of Galilee was on the Northwest shore of the Sea of Galilee. It was a prominent location of Jesus’ early ministry and some scholars believe it was the place Jesus considered His new hometown.
The synagogue and town of Capernaum are referred to in a number of events in Jesus’ ministry. And so from Jesus’ close relationship with Capernaum, it would be expected that the people of the town would be familiar with Him. And yet they were astonished by Him during this time in their synagogue.
And their astonishment was directed towards the authority by which He taught. Jesus amazed the scholars in the Temple in Jerusalem when He was twelve years old, and His knowledge and command of the Old Testament scriptures continued to develop during the following years leading up to His adulthood, and this moment in the synagogue. And what is noticeable about Jesus’ teaching authority is that He did not teach using the same method and style of the scribes.
The teaching custom of that time, and as it is most always at any point in time, was for the scribe to quote the interpretations of scripture made previously down through the years by those considered to be the best scholars. That would mean no contemporary teacher would have genuine authority emanating from himself. All teaching, therefore, would have to be based upon authority acquired from others.
But Jesus had the authority living in Himself. It appears to be a combination of Jesus being the Son of God and His diligent study of scripture, as He applied His wisdom and understanding. And the force of His personality, His deity, and command of the scriptures provoked a demon out into the open, as this time in the synagogue continued to unfold.