Despite having sung and heard John Henry Hopkins carol "We Three Kings" hundreds of times I have never before associated the gifts of the Magi with the Blessed Trinity.
Hopkins final verse, however, is quite instructive:
Glorious, then, all hail him arise,
King, and God, and Sacrifice
Sounds through the earth and skies
The Magi and Their Gifts
Typified in the Old Testament by the Queen of Saba (Sheba), who entered Jerusalem "with a great train, and riches, and camels that carried spices, and an immense quantity of gold, and precious stones" in order to ascertain King Solomon's greatness (III Kings 10), the three Magi entered Jerusalem bearing gold, frankincense, and myrrh for the newborn King. The Fathers see in their gifts omens of Christ's life:
The Golden Legend, written in A.D. 1275 by Jacobus de Voragine, Archbishop of Genoa, describes the gifts thus:
...by these three be signified three things that be in Jesu Christ: The precious Deity, the soul full of holiness, and the entire Flesh all pure and without corruption. And these three things be signified that were in the ark of Moses. The rod which flourished, that was the Flesh of Jesu Christ that rose from death to life; the tables wherein the commandments were written, that is the soul, wherein be all the treasures of sapience and science of Godhead. The manna signifieth the Godhead, which hath all sweetness of suavity. By the gold which is most precious of all metals is understood the Deity; by the incense the soul right devout, for the incense signifieth devotion and orison; by the myrrh which preserveth from corruption, is understood the Flesh which was without corruption.