Pinyin: fàng xià tú dāo, lü dü ché ng fó
Explanation: words from Buddhists to persuade people to change evil and do good. It is a metaphor that once an evil person realizes his crime and is determined to mend his ways, he can still become a good person quickly.
Origin: Song Shi Puji's Five Lights Will Be Yuan, Volume 53: "Guange is a man who kills without blinking an eye. Put down his butcher's knife and become a Buddha."