‘And coming into his own country he taught them in their synagogue, insomuch that they were astonished, and said, “From where has this man this wisdom, and these mighty works?”
Jesus arrives back in the place where He was brought up and teaches in their local synagogue where He had once learned so much, and to which He had often gone in order to study the Scriptures. Who better than they should have known how unique He was? But they had failed to pierce the veil and saw only the town carpenter. Thus when they heard Him teach they were astonished. News of His mighty works and preaching success had filtered through from Capernaum (Luke 4:23), but they did not really believe it. For where could such skill and such mighty works have come from? They just could not believe that God would so anoint a local boy with whom they were so familiar. He was simply getting above Himself and would no doubt bring disgrace on the town.
The synagogue was the centre of a town or village's life, where weekly worship was conducted, male children were taught to read the Scriptures, justice could be sought, religious discipline would be exerted, sometimes by beatings, Scripture teaching would be given, and on the Sabbath any prominent visitor would be invited to speak. The reading and teaching of Scripture was a central part of its worship.
We are not actually told that this is in Nazareth, and that may be deliberate. Matthew does not want it to be seen as simply a local town rejection, but as one by His ‘home country'. But the description below points to Nazareth.