If there is any value that does have value, it must lie outside the whole sphere of what happens and is the case. For all that happens and is the case is accidental. What makes it non-accidental cannot lie within the world, since if it did it would itself be accidental. It must lie outside the world. So too it is impossible for there to be propositions of ethics.
Propositions can express nothing that is higher.
It is clear that ethics cannot be put into words. Ethics is transcendental. How things are in the world is a matter of complete indifference for what is higher. God does not reveal himself in the world. It is not how things are in the world that is mystical, but that it exists.