One thought leads to another and lo – Bankei turns up to say something about the Unborn.
Actually, this enigmatic Zen master used the word Fu-shō – Unborn – to sum up his entire teaching:

Your unborn mind is the Buddha-mind itself, and it is unconcerned with either birth or death.  As evidence of this, when looking at things, you’re able to see and distinguish them all at once.  And as you are doing that, if a bird sings or a bell tolls, or other noises or sounds occur, you hear and recognize each of them too, even though you haven’t given rise to a single thought to do so.  Everything in your life, from morning until night, proceeds in this same way without your having to depend upon thought or reflection.  But most people are unaware of that; they think everything is a result of their deliberation.  That is a great mistake.

If you harbor the least notion to become better than you are or the slightest inclination to seek something, you turn your back on the Unborn.  There is neither joy nor anger in the mind you were born with – only the Buddha-mind with its marvelous illuminative wisdom that enlightens all things.

– Bankei

The Unborn: The Life and Teachings of Zen Master Bankei, 1622-1693
Translation by Norman Waddell