"Fudo Myoo grasps a sword in his right hand and holds a rope in his left hand. He bares his teeth and his eyes flash with anger. His form stands firmly, ready to defeat the evil spirits that would obstruct the Buddhist Law. This is not hidden in any country anywhere. His form is made in the shape of a protector of Buddhism, while his embodiment is that of immovable wisdom. This is what is shown to living beings."
"Seeing this form, the ordinary man becomes afraid and has no thoughts of becoming an enemy of Buddhism. The man who is close to enlightenment understands that this manifests immovable wisdom and clears away all delusion. For the man who can make his immovable wisdom apparent and who is able to physically practice this mental dharma as well as Fudo Myoo, the evil spirits will no longer proliferate. This is the purpose of Fudo Myoo's tidings."
"What is called Fudo Myoo is said to be one's unmoving mind and a unvacillating body."
From "The Unfettered Mind" by Takuan Soho
(Translated by William Scott Wilson, published by Kodansha International, 1986, p. 20 - 21)