肉を切らせて骨を断つ niku o kirasete hone o tatsu Let Them Cut Your Flesh, and Cut Their Bone

肉 is flesh and 骨 bone. 切らせて, kirasete, is the causative of 切る, to cut: letting them cut, the wound taken on purpose. 断つ, tatsu, is to cut through. The saying is also written with the ending 骨を切る, hone o kiru, which the dictionaries enter beside it. The fuller form runs in steps: let them cut your skin and cut their flesh; let them cut your flesh and cut their bone.

The figure is older than its earliest known words. The 兵法秘伝書 Heihō hidensho, a manual of the martial arts printed in 1701, its colophon reading 山本勘介記, written by Yamamoto Kansuke, teaches winning by the mutual strike: I let them cut my hand, and cut the enemy's head. The National Institute of Japanese Literature gives the authorship as 伝, attributed.

The 葉隠 Hagakure, the teaching of the Saga retainer Yamamoto Tsunetomo, compiled from 1710, has the skin and the bone: be cut in the skin yourself, and cut the bone. It looks reckless, but unless one becomes reckless, victory is uncertain. Here the swordsman is cut, rather than letting them cut, and there is no flesh.

Kumamoto Sanemichi's sword manual of February 1893, the 武道教範 Budō kyōhan, sets the enemy cuts my skin and I cut his bone under a sword poem on the crossed blades, glossed as if one steps in deep even one step, beyond it is paradise, and says it speaks of resolve roused to the full.

In a storyteller's tale printed in December 1893, a gambler sets the words against the sword teachers, who, he says, put their own bodies first: let the enemy cut your skin and cut his flesh, then let him cut your flesh and cut his bone, let him take your arm and take his head: that is the gamblers' way of brawling.

In a storyteller's tale of 1917, a sword teacher gives the saying as the secret of all swordsmanship and says what it means: Try to strike your opponent with the tip of the wooden sword and you will never strike him; unless you leap in expecting to be struck yourself, meaning to strike his head with the guard of your sword, you will never strike him.

In his kendō manual of 1920, the 日本剣道教範 Nihon kendō kyōhan, Takano Sasaburō sets the saying under the heading winning by the mutual strike, beside the example the 1701 manual gives: letting them cut your hand and cutting the enemy's head.

A storyteller's tale of 1903 has a follower of Yagyū Jūbei shout the saying as the secret of swordsmanship. A book of 1922 says Araki Mataemon impressed it on his companion before the Iga-goe vendetta of 1634, as a part of the Yagyū school's secret. Neither names a source in a school's own writing, and the telling that gives the saying to Araki, first known in 1922, nearly three centuries after the fight, is a legend.

In John Stevens's 2007 translation of Ueshiba Morihei: In old-time swordsmanship it was said, "Allow the skin to be cut in order to cut the flesh; let the flesh be cut in order to cut to the bone." That is, sacrifice a cut to your skin or even to your flesh to get close enough to cut to your enemy's bone. However, in today's world we do not want the skin to even get scratched.

As our history of the saying reads the sword texts, the saying is about going in: the flesh is the price of the distance closed, and the bone is what one can reach only from there. The dictionaries read it as an exchange, and JMdict's English leads with to lose a battle to win the war. Both senses are the saying's.

A swordsman's teaching older than its earliest known words: a manual of the martial arts printed in 1701 teaches the mutual strike as letting them cut one's hand to cut the enemy's head, and the Hagakure of the 1710s teaches being cut in the skin to cut the bone; the words with flesh and bone are first known in print in 1893, in the witnesses read.