Who said "Train so your skill works at any moment."?

Miyamoto Musashi (c. 1584–1645). Source: The Book of Five Rings, Earth (The Way of Strategy).

What is the original Japanese?

何時にても役に立やうに稽古し、萬事に至り役に立樣に. Translated from the original Japanese by Spartan Surfers.

Train so your skill works at any moment.

Miyamoto Musashi, The Book of Five Rings, Earth (The Way of Strategy)

The source

"Train so your skill works at any moment." Miyamoto Musashi said it in The Book of Five Rings, Earth (The Way of Strategy). Translated from the original Japanese by Spartan Surfers.

"何時にても役に立やうに稽古し、萬事に至り役に立樣に"

Original Japanese, The Book of Five Rings, Earth (The Way of Strategy). Japanese: Miyamoto Musashi (Kinkodo, 1909), NDL digital text.

Who said it

Miyamoto Musashi (c. 1584–1645). Undefeated swordsman who wrote The Book of Five Rings in a cave a few weeks before he died.

Questions

Who said "Train so your skill works at any moment."?: Miyamoto Musashi (c. 1584–1645). Source: The Book of Five Rings, Earth (The Way of Strategy).
What is the original Japanese?: 何時にても役に立やうに稽古し、萬事に至り役に立樣に. Translated from the original Japanese by Spartan Surfers.