fällt zusammen hinein?

人を呪わば穴二つ
(Hito wo norowaba ana futatsu; “If you place a curse, [dig] two holes”)

Definition:

If you try to harm others, harm will come (back) to you. More literally, if you curse someone to death, their dying grudge will afflict and kill you in turn, so that your initial malevolence results in two graves being needed. “Curses, like chickens, come home to roost.”

Breakdown:

We begin with the noun 人 (hito), “person,” marked as the object of a verb by the particle を (wo). What acts on the person is the only verb present: 呪う (norou), in imperfective form with the hypothetical particle ば (ba) attached. This is followed by a noun phrase comprising noun 穴 (ana), “hole,” and number 二つ (futatsu), “two.” We can imagine some elided final verb to make a complete sentence, but usage examples suggest that the whole saying is commonly used as a noun phrase.

Notes:

Making the “holes” (穴) explicitly graves (墓, haka) is considered an error. On the other hand, it’s okay to use the perfective form 呪え with the conditional ば instead of imperfective and hypothetical – in other words, it’s okay to say “when” rather than “if.”

This phrase comes to us from the Ise Monogatari, a Heian-era narrative poetic collection.

Example sentence:

「止めろ！たとえ敵を討っても、彼奴の味方が復讐をしにやってくるだけなんだ。人を呪わば穴二つだよ」

(“Yamero! Tatoe teki wo utte mo, aitsu no mikata ga fukushuu wo shi ni yatte kuru dake nanda. Hito wo norowaba ana futatsu da yo.”)

[“Stop! Even if you strike down your foe, his allies will only come for revenge. If you go to kill someone, dig your own grave too.”]