Who told Joseph to go to Bethlehem?

According to the second chapter of Luke, Caesar Augustus ordered that all people were to be taxed and, therefore, had to return to their "own city." Joseph had to travel from Nazareth to the "city of David," another name for Bethlehem, because he was of the "lineage of David."

Mary went with Joseph, even though it was almost time for her to give birth. Joseph's return to Bethlehem and the birth of Jesus there fulfilled the prophecy from Micah 5:2, which reads, "But thou, Bethlehem Ephrathah, though thou be little among the thousands of Judah, yet out of thee shall he come forth unto me that is to be ruler in Israel whose goings forth have been from of old, from everlasting."