There are many prophecies in the Old Testament that speak to the nature, mission and coming of Christ. Two of them would stand out more than the rest to the Magi.
Numbers 24:17: “I see him, but not now; I behold him, but not near; A star shall come forth from Jacob, A scepter shall rise from Israel, And shall crush through the forehead of Moab, And tear down all the sons of Sheth.
Isaiah 60:1-7: "Arise, shine; for your light has come, And the glory of the LORD has risen upon you. For behold, darkness will cover the earth And deep darkness the peoples; But the LORD will arise upon you, and His glory will appear upon you. Nations will come to your light, and kings to the brightness of your rising...They all gather together; they come to you. Your sons will come from afar...The wealth of the nations will come to you. A multitude of camels will cover you, the young camels of Midian and Ephah; All those from Sheba will come; They will bring gold and frankincense and will bear good news of the praises of the LORD. All the flocks of Kedar will be gathered together to you, The rams of Nebaioth will minister to you...
The prophets are precise in their declarations. Balaam, son of Beor, who also lived in the East, speaks of the star, literally Christ as the Star of Jacob. Isaiah the Prophet names several of Abraham's descendants who lived in the East bringing frankincense and myrrh, including Nebaioth, coming to minister to Him.
But, what about the star? What more can be learned about why the star was so important to the Magi to compel them to follow it to find Christ.