I know the source well.

I know the spring well,
which carves its way out,
racing into darkness,
refreshing everything around
and itself is bright,
from it all light rises,
even though it belongs to the night.

I know that stream,
that it cannot be crossed,
that its powerful current
can even flood hell,
earth and heaven drink from it,
yet I cannot see the bottom,
even though it is in the midst of night.

Here it calls forth creatures
and satisfies them with waters,
giving of itself,
quenching my thirst,
I recognize it in Bread –
the source of life glistens
in the depths of this earthly night.

(paraphrase of John's poem The Spring)