Lao Tse on a blue cow

Lao Tse on a blue cow

Lao Tse, on a blue cow,

Is leaving KankokuKan

In West

His farewell is

His purity, which is

Always a way of his thinking,

Always a channel of his considering

Always a logic of his pondering

It is a law to understand the essence of the universe. 

(Trails of his thinking shine like water.)

The essence of the essence is a gate of the universe

He came out of the gate, he passed through the gate

He came through the gate, he came out of the gate

It was a long, long journey through the womb of the Mother

(How many times I was reborn!)

Now, this journey comes to end finally

Good bye

Said Lao Tse,

Closing the last gate of the gates

(Riding, far, on a blue cow)

P.S.
Please let me know how to spell"函谷関", Kankokukan, alphabetically by Chinese pronouciation, in the first stanza, if you may know it.