In an episode of Person of Interest, an American sci-fi crime drama, a detective is directed by his superior to turn in his badge and service gun. When asked by his partner what it is all about, he replies, “Just chickens coming home to roost.” How does the investigation of an allegedly dirty cop have anything to do with chickens?

“Chickens come home to roost” is a proverbial expression meaning that one’s past wrongdoings will eventually rebound on oneself. According to The American Heritage Dictionary of Idioms, the fact that farm chickens go out to forage during the day and return, by night, to the safety of their henhouse to roost, has long been common knowledge. But it was not until 1809, when Robert Southey wrote, “Curses are like young chickens, they always come home to roost” (The Curse of Kehama), that the idea was figuratively used. It is easy to find its abbreviated versions from then on, such as “the debt chickens come home to roost as the immediate crisis recedes” (The New Daily, 13 April 2020).

Unlike the saying “reap the harvest” which may refer to both positive and negative consequences, “chickens come home to roost” is often connected with undesirable impacts arising from past misdeeds or indiscretions. So, if you are trying to reassure a friend that what he did will bear positive fruit, you may want to leave homing chickens out of the conversation.

在日本電影《檢察狂人》中，木村拓哉飾演的檢察官眼見殺害青梅竹馬的凶手因訴訟時效已過而逍遙法外，心有不甘，選擇做撲火飛蛾，為求伸張公義，不惜以身試法。面對後輩質問，他冷然道：“為了頑強地生存下去，只能執着於自己的正義。”對自詡替天行道的人而言，讓惡人“自食其果”不能等老天，只能靠自己。

“自食其果”這個成語與佛教因果觀密不可分。佛教《正法念處經》有偈云：“自業自得果，眾生皆如是。”佛教主張種善因得善果，種惡因得惡果；待因緣成熟後，必會有所報，只是不一定在今世發生。果報隨善惡業有好有壞，但成語“自食其果”單指惡果，形容自己做壞事，自己受害。

人力時有窮盡，天道永遠昭昭，如果人們對此深信不疑，會否更能化戾氣為祥和？不過，比起為求好報或懼怕受罰的行善或不作惡，更難能可貴的是不為什麼的善良。你聽說過麥嘜小朋友嗎？“有人在的時候，麥嘜很乖。沒有人在的時候，沒有人罰，沒有人讚，麥嘜依然很乖。沒有人在身邊時都乖，是發自內心，真正的乖。”（《2001麥嘜大道理小月曆》）