The Warrior’s Word, Dependable as Gold and Steel in Chinese / Japanese...

武士の一言金鉄の如し is an old Japanese proverb about the value of the word of a warrior.

Here are a couple of versions of how this can be translated:

A warrior's single word is as unchanging and reliable as gold and steel.
A warrior's promise is as dependable as gold, and his [scabbard contains] untarnished steel (a sword).

Note: Sometimes this phrase is written as 男子の一言、金鉄の如し (danshi no ichigon kintetsu no gotoshi)

Note: Because this selection contains some special Japanese Hiragana characters, it should be written by a Japanese calligrapher.