The thirsty deer of Psalm 42 stands at the foot of the cross in the Apse Mosaic, the crown jewel of the twelfth-century church of San Clemente in Rome. In fact, three deer constitute the foundation of the glowing composition, which offers a condensed visual account of all salvation history and the work of the three Persons of the Trinity.
At the bottom, two deer slake their thirst from the four rivers that flow from Eden (Genesis 2:10). Just above, one deer, encircled by a red serpent, drinks from a great body of water. Is this the primeval deep (Genesis 1)? Or the river of the water of life (Revelation 22:1)? The image may recall an ancient belief that deer eat venomous snakes, neutralizing their poison with copious quantities of water. Psalm 42 figured prominently in baptismal liturgies, and medieval viewers would have recognized in the scene allusions to the soul’s thirst for God’s grace and deliverance from deadly sin through the sacrament.
Above the lone deer spreads an acanthus plant. Greeks associated its thorny, aromatic leaves with victory over suffering, and Christians with resurrection; in John’s Gospel (19:2), the soldiers plait a crown of akanthos for Jesus. Here the cross rises from the plant and stretches nearly the height of the apse, to where a divine hand reaches down to crown him with a victory wreath. The cross is surrounded by thorns and studded with twelve doves, symbolizing the apostles in their innocence (Matthew 10:16).
The gold background that fills the apse represents the divine glory that fills the world through the discrete actions of the Triune God: the original creation (Eden), Jesus’s victory on the cross, and the renewal of creation through the Spirit of the crucified and risen Christ.
Oakeshott, Walter. 1967. The Mosaics of Rome: From the Third to the Fourteenth Centuries (London: Thames & Hudson)
42As a hart longs
for flowing streams,
so longs my soul
for thee, O God.
2My soul thirsts for God,
for the living God.
When shall I come and behold
the face of God?
3My tears have been my food
day and night,
while men say to me continually,
“Where is your God?”
4These things I remember,
as I pour out my soul:
how I went with the throng,
and led them in procession to the house of God,
with glad shouts and songs of thanksgiving,
a multitude keeping festival.
5Why are you cast down, O my soul,
and why are you disquieted within me?
Hope in God; for I shall again praise him,
my help 6and my God.
My soul is cast down within me,
therefore I remember thee
from the land of Jordan and of Hermon,
from Mount Mizar.
7Deep calls to deep
at the thunder of thy cataracts;
all thy waves and thy billows
have gone over me.
8By day the Lord commands his steadfast love;
and at night his song is with me,
a prayer to the God of my life.
9I say to God, my rock:
“Why hast thou forgotten me?
Why go I mourning
because of the oppression of the enemy?”
10As with a deadly wound in my body,
my adversaries taunt me,
while they say to me continually,
11Why are you cast down, O my soul,
my help and my God.
43Vindicate me, O God, and defend my cause
against an ungodly people;
from deceitful and unjust men
2For thou art the God in whom I take refuge;
why hast thou cast me off?
because of the oppression of the enemy?
3Oh send out thy light and thy truth;
let them lead me,
let them bring me to thy holy hill
and to thy dwelling!
4Then I will go to the altar of God,
to God my exceeding joy;
and I will praise thee with the lyre,
O God, my God.