A proverb warning that when you curse someone, misfortune will come back to you as well—'if you dig one grave for them, you need two for both.'
復讐の念で行動している彼に友人は『人を呪わば穴二つ』と諭した。
A friend admonished him, who was acting out of revenge, saying, "If you curse someone, you'll need two graves."
悪口を言い続けた結果、自分の信用も失った。まさに人を呪わば穴二つだ。
As a result of continuing to speak ill of others, he lost his own credibility. Truly, if you curse others, you need two graves.