When Jesus was born, he was visited first by shepherds, and then by what have become known as the “Three Kings.”
However, the Bible never says there were three, and they are never identified as kings. It has been assumed the since there were three gifts, there must have been three men.
The men were more properly “magi.” They studied astronomy, which is how they found the star, which was to them in the east, since they probably came from the area of Persia. (East of Israel, not east of New York, where the carol was written.)
Now, what about those gifts? Why those particular items?
Gold is the easiest to figure out. Gold has always represented royalty, wealth. Even Abraham was said to be rich in gold.
Frankincense is often said to be a symbol of Jesus’ priestly role. Frankincense is an aromatic gum obtained from a small tree. The gum is drained from the tree by slicing the bark, then hardened and often turned into incense. It was one of the ingredients in the incense for the tabernacle mentioned in Exodus. Whether or not the magi would have know about the Jewish laws relating to the use of frankincense is a toss-up, but frankincense can also be used as a medicine and was highly valued.
Myrrh is often seen as prefiguring his death as it was used in embalming in Egypt. It is also seen as a symbol of suffering. Again, whether or not the magi knew what was to happen to Jesus, and how he would die, I believe is doubtful. Myrrh is another gum resin obtained from a thorny bush, used in the sanctuary incense. It is still used, mixed with frankincense, as an incense in most orthodox churches. It was a sought-after perfume ingredient. But it too was used as medicine, used to heal wounds and sometimes alleviate pain. It was offered to the dying Jesus on the cross as it dulled the senses. (He refused it.)
These gifts would have been well known to men from Arabia. They were practical, valuable gifts, fit for a king and given in joy and worship. Whatever you offer to him this season, offer from your heart, with joy and wonder.
When they saw the star, they rejoiced exceedingly with great joy. After coming into the house they saw the Child with Mary His mother; and they fell to the ground and worshiped Him. Then, opening their treasures, they presented to Him gifts of gold, frankincense, and myrrh. -Matthew 2:10-11