There is something about a lullaby that is timeless and most sacred. The tradition since time immemorial has been between mother and child. Very rarely has it been used in the context of star-crossed lovers.
Ennis's lullaby is at the center of this scene, which is at the center of the entire film. It is the heart of hearts -- center of centers -- core of cores. As the Poet Rilke had envisioned:
Center of all centers, core of cores,
almond self-enclosed, and growing sweet--
all this universe, to the furthest stars
all beyond them, is your flesh, your fruit.
Now you feel how nothing clings to you;
your vast shell reaches into endless space,
and there the rich, thick fluids rise and flow.
Illuminated in your infinite peace,
a billion stars go spinning through the night,
blazing high above your head.
But in you is the presence that
will be, when all the stars are dead.
.
Truly -- most truly -- their love shall endure (even if only in most tenuous memory): until all the stars are dead.