The Youngest Son is also known as "Linked Mountains," it signifies an Insurmountable Obstacle necessitating stillness.
"The Youngest Son represents a guardian, his direction is in the Northeast. It is the mysterious place where all things begin and end, where birth and death pass into one another." Book III, The Commentaries
The Hexagram turns on the problem of achieving a quiet heart. It is difficult to bring quiet to the heart. But, when a person has accomplished this she no longer sees the outside world as the struggle and tumult of individual beings. She has achieved true peace of mind and understands the great laws of the universe and for acting in harmony with them.
Book I, The Text
The earliest I Ching that we know about is called Lianshan , meaning "linked mountains,'" a reference to the doubled mountain image of Hexagram 52. Another name given for the Lianshan was Manifestation of Change in the Mountains.
Faithful, kind, loving and protective is the Youngest Son.
