"To know the strong masculine principle, yet abide by the gentle female principle is like being the valley of the world where all rivers will flow into.
This is alike all virtue which will merge into the subtle Tao.
Being a valley of the world and not depart from the true nature, once can return to original pureness like an infant.
When one knows the white that is splendor, yet holds on to the black that is humble and lowly.
He can be a standard of the world.
Being a standard of the world and not deviate from true nature, one is able to return to the void
of Tao.
To know what is honor, yet abide by the dishonored, is like a valley of the world which is modest and humble.
Being the valley of the world makes possible the true virtue to be complete and sufficient.
And hence can return to simplicity.
When the nature of simplicity is being manifested, it results into various vessels.