Why Bethlehem?

After the anouncement by the angels, the shepherds knew where to go.  How was this possible?  In Bethlehem, the shepherd's tower, Migdal Eder, was the place the priestly shehperds would take lambs to birth their newborns.  These newborn lambs were reserved especially for Temple sacrifice, and had to be carefully wrapped to protect them from injury and keep them spotless as acceptable sacrifices. 

From the moment of His birth, every prophesy about Jesus was carefully fulfilled.  He came to offer himself as our sacrifice for sin.