This is from a book called Eat Sleep Sit: My Year at Japan’s Most Rigorous Zen Temple, written by Kaoru Nonomura and translated by Juliet Winters Carpenter. Nonomura has been suffering through the first week of training at Eiheiji Monastery; he comments on the dressing codes at the place, and particularly on the use of “the mantle or kesa, which derives from an everyday sari-like garment of ancient India that was transformed into something sacred”. This is the story behind the mantle:

“During his stay in China, Dogen saw monks place their mantles on their heads and hold their palms together in reverence. He wrote that this holy sight filled him with such irrepresible joy that he wept until the collar of his robe was soaked with tears.

Concerning the material for the mantle, he specified that it should be made from pure materials, and decreed that the following ten types of discarded cloth are especially pure:

Cloth chewed by an ox.
Cloth gnawed by rats.
Cloth scorched by fire.
Cloth soiled with menstruation.
Cloth soiled by childbirth.
Cloth discarded at a shrine.
Cloth discarded at a graveyard.
Cloth discarded in petitions to the gods.
Cloth discarded by king’s ministers.
Cloth laid over the dead.

Monks would gather scraps of such discarded cloth and patch them together. Dogen expounded further on the meaning of such rags, known as funzoe (literally “excrement-sweeping cloth”);

When collecting discarded bits of cloth, some will be silk and some will be cotton. But once they are used to make a mantle, they are neither silk nor cotton but funzoe. Cloth that is funzoe is not silk, nor is cotton.

If a human being should become funzoe, that person would be no longer a living creature, but funzoe; and if a pine or a chrysanthemum should become funzoe, it would no longer be vegetation but would indeed be funzoe.

Only by grasping the principle that funzoe is neither silk nor cotton nor jewels can one understand funzoe and come face to face with it. Those who are not convinced that a mantle is silk or cotton cannot begin to understand funzoe. Even if someone wore a mantle of rough cloth all his life in a spirit of humility, as long as he was distracted by the material and appearance of the cloth, faithful transmission of Buddha’s teachings would never be possible.”