what do Robert Bly "The Third Body " mean?

Question

A man and a woman sit near each other, and they do
not long
at this moment to be older, or younger, nor born
in any other nation, or time, or place.
They are content to be where they are, talking or
not-talking.
Their breaths together feed someone whom we do
not know.
The man sees the way his fingers move;
he sees her hands close around a book she hands
to him.
They obey a third body that they share in common.
They have made a promise to love that body.
Age may come, parting may come, death will come.
A man and a woman sit near each other;
as they breathe they feed someone we do not know,
someone we know of, whom we have never seen.

Answer 1

Committed love.