On coming to the house, they saw the child with his mother Mary, and they bowed down and worshiped him. Then they opened their treasures and presented him with gifts of gold and of incense and of myrrh. Matthew 2:11
“There is something more that must be understood about the gold, incense and myrrh. Solomon testifies that gold symbolizes wisdom when he says, “A pleasing treasure lies in the mouth of the wise” (Proverbs 21:20). The psalmist bears witness to that incense which prayer offers to God when he says, “Let my prayer ascend as incense in your sight” (Psalm 141:2). The myrrh indicates the mortification of our bodies, of which the holy church speaks of its workmen who strive even unto death on behalf of God” (Song 5:5).
And so do we too offer gold to the newborn king if we shine in his sight with the brightness of the wisdom from on high. We too offer him incense if we enkindle on the altar of our hearts the thoughts of our human minds by our holy pursuit of prayer, so as to give forth a sweet smell to God by our heavenly desire. And we offer myrrh if we mortify the vices of our bodies by our self-denial. Myrrh brings it about, as I have said, that dead bodies do not decompose. For a dead body to decompose is the same as for the human body of ours to become a slave to the decay of dissoluteness, as is said by the prophet: “The pack animals have decomposed in their own dung” (Joel 1:17). This indicates fleshly-minded persons who end their lives in the stench of dissoluteness. Therefore we are offering myrrh to God when we employ the self-restraint to keep this earthly body of ours from decomposing through decadence.”
Gregory the Great (540-604) was Pope and one of the Four Doctors of the Western Church. Forty Gospel Homilies 10.6. PL 76:1113; CS 123:58-59.