St. Matthew wrote his Gospel as good news for the Jewish community. It was read in the Synagogue Sabbath by Sabbath after the Temple fell in 70AD. Matthew wrote about 80 AD. Matthew is proclaiming in Synagogues that Jesus is the Messiah and the Greater Moses. When the faithful new followers of Jesus who were Jewish and followed the tradition in Jerusalem, heard the 10 Commandments of Moses read in the Sabbath worship, they would then hear a new Christian leader stand up afterwards and read Jesus' new Commandments which we today call the Beatitudes.
In 2017, we have lost the Jewish understanding of worship for Christians. We have taken the roots away and admire the New Testament as if it were an arrangement of rootless flowers as opposed to its true flavor and meaning. This is especially true for the Gospels. The Beatitudes are Jesus commandments and call to us living today as Christians, not some decoration on the shelf!