불입호혈 부득호자

Etymology
From "超曰 不入虎穴 不得虎子," literally, "Ban Chao said that no tiger's den entered, no tiger's cub gathered," as recorded in "Biographies of Ban Chao and Liang Jin" of Book of the Late Han Volume 47.

Noun

 * 1) (the notion of) nothing ventured, nothing gained; (the notion of) no pain, no gain