Namaste is a way of greeting to a person just like good morning, sayonara etc. Both the hands joined to make one to let the greeter remember that the person to whom he is greeting is one but still it is neither one nor two but it is beyond both ie salute to the Godliness in the other. This is real definition of achieving enlightenment or Jesus-Consciousness or Buddha-Consciousness etc etc. When a person who has not attained it greet with namaste to an enlightened one or master or friend/fellow- in Zen, then the other also responds to him/her with namaste. This namaste has very deep meaning because the master or enlightened one is also paying respect to the other as he knows that he/she is just a few step behind only and then he/she will also become enlightened. Then time cease to happen and both will be on same platform. So it is just matter of time that you are at this platform but master is welcoming him/her now, in the world of enlightened ones, since time cease to exist for the enlightened master.
In Zen also this is a tradition that enlightened one too bows to the unenlightened ones in respect.
Each hand represent one eye. So when a person stops seeing world from two eyes and begins looking at world like a child but this time from third eye. Child’s innocence can be perverted in future but innocence of the third eye is pure and permanent or more accurately eternal, as it already passed through the experiences of life. This third eye is located at centre of both and is able to see inside the body or the other. This is called common sense or intuition or creativity if not fully developed but its presence in one shows that the person is on edge.
This third eye can be activated using both the eyes but it functions neither like both nor like one but beyond both. It is called Divya-Drishti by Krishna in the Geeta. Looking the world from these eye is such a bliss, ananda, that those experienced it expressed that the world disappears for them. The world is Maya or just a drama in their words. The person starts living in nature and enjoying the nature, its beauty, animals, flowers etc to its deepest meanings. Abundance in everything like love is his message. Since in nature tree, animals or creatures are given capacity to produces abundant seeds just for one tree or flower or fruit to nurture to its best. His love is such that for one person to get enlightened he produces millions, out of abundant love he takes no chance! it seems.