Before you embark on a journey of revenge, dig two graves.

Attributed in Lillet Walters (2000), Secrets of Superstar Speakers; attributed in English sources as a "Japanese proverb" as early as 1924. Compare with a Japanese proverb 人を呪わば穴二つ (Hito wo norowaba ana futatsu), "Curse someone, then you will get two graves."