This this part of the chapter Matthew is telling us how the people of Nazareth (the town which Jesus grew up in) were astonished and shocked with the wisdom and power he had , they were confused about how and where he got this wisdom and power and knowledge because they knew his entire family they knew his father was a carpenter who had no special abilities so because of this they were confused and refused to believe in him and refuse to believe he is who he says he is (which is the son of God)