Why did the Magi bring gold, frankincense, and myrrh?

• Biblical Archaeological Society  online article about "why."  An excerpt from their longer article “The Magi’s Gifts—Tribute or Treatment?” in Biblical Archaeology Review, January/February 2012.
  
  
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  Gift of Frankincense

  Frankincense comes from tree resins. Frankincense was once greatly valued throughout the Middle East from Rome to India. It was very expensive and has a wonderful fragrance. Frankincense occurs fifteen times in the Bible. A quick survey reveals it was used primarily in biblical times for making incense (Exodus 30:34) and as an ingredient in sacrifices (Leviticus 2:1-2). Song of Solomon 3:6; 4:14 reveals it was also an ingredient in perfume. Since frankincense was primarily used in the Bible in worship, frankincense speaks of the worship of God.

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  Gift of Myrrh

  Myrrh is extruded from the gum of the Commiphora myrrh plant. Myrrh was less expensive than frankincense, but was still highly valued. Myrrh is referred to seventeen times in the Bible and is first mentioned in Genesis 37:25, where it was being carried by camels in a caravan. Myrrh was used for a variety of purposes in biblical times as a perfume (Song of Solomon 1:13; 3:6; 4:6, 14; 5:1, 5, 13), an anesthetic, for burial embalming (John 19:39), as an ingredient in anointing oil (Exodus 30:23-25), and to deodorize clothes. According to Esther 2:12, it was also used in a cosmetic for women. John 19:39 records that myrrh was used in Jesus’ burial.

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