歃血为盟 Make a blood alliance
Explanation
歃血为盟是指古代结盟时，双方在祭祀仪式上，将牲畜的血涂抹在嘴唇上，以表示诚意和决心。
Making a blood alliance refers to the ancient practice of making an alliance. During a sacrificial ritual, both parties would smear the blood of animals on their lips to show sincerity and determination.
Origin Story
话说战国时期，秦国虎视眈眈，中原各国人心惶惶。魏国国君魏王为了对抗秦国，便派使者四处联络，寻求同盟。一日，使者来到赵国，赵王召见使者，双方相谈甚欢，决定结为盟友，共同抗击秦国。为了表示决心，赵王提议举行歃血为盟的仪式。仪式在赵国太庙举行，双方将宰杀的羊羔血涂在嘴唇上，然后在盟约上签字画押，并郑重宣誓。此后，赵魏两国亲如兄弟，共同抵御秦军侵犯，成为一时佳话。
In the Warring States period, the Qin state was eyeing the Central Plains covetously, causing the hearts of the various states to tremble with fear. To resist the Qin state, the king of Wei sent envoys everywhere to seek alliances. One day, an envoy arrived in Zhao, and the king of Zhao received the envoy. Both sides were delighted and decided to become allies to fight against Qin together. To show their determination, the king of Zhao proposed a blood alliance ceremony. The ceremony was held in the Zhao ancestral temple. Both sides smeared the blood of a sacrificed lamb on their lips, then signed and sealed the pact, and solemnly swore an oath. After this, the kingdoms of Zhao and Wei became close as brothers, resisting the invasion of the Qin army together, and this became a story for the ages.
Usage
用于形容双方真诚地结盟，也常用于比喻决心坚定，同心同德。
It is used to describe the sincere alliance between both parties, and it is often used to describe a strong will and unity.
Examples
-
刘邦和项羽曾歃血为盟，约定共同抗击秦军。
Liú Bāng hé Xiàng Yǔ céng shà xuè wéi méng, yuēdìng gòngtóng kàngjī Qínjūn。
Liu Bang and Xiang Yu once made a blood alliance, agreeing to fight against the Qin army together.
-
为了表达诚意，双方决定歃血为盟，永结兄弟情谊。
Wèile biǎodá chéngyì, shuāngfāng juédìng shà xuè wéi méng, yǒng jié xiōngdì qíngyì。
To express their sincerity, both sides decided to make a blood alliance and forever forge fraternal bonds of friendship.