[Source] Sima Qian, "Records of the Grand Historian: Biographies of Lord Pingyuan and Lord Yuqing" (Western Han Dynasty).
[Meaning] Mao Sui: a retainer of Lord Pingyuan of the State of Zhao during the Warring States period; "jian" means to recommend or nominate. This idiom refers to a retainer named Mao Sui who volunteered himself. It is used metaphorically to describe someone who volunteers for a task.
[Historical Story]
Lord Pingyuan of the State of Zhao was one of the four renowned noblemen of the Warring States period. It is said he had several thousand retainers, among whom was Mao Sui. In 257 BC, the Qin army besieged Handan, the capital of Zhao. King Huiwen of Zhao sent Lord Pingyuan to the State of Chu to request military assistance. However, the King of Chu was not easily persuaded, so Lord Pingyuan took twenty of his retainers with him. If negotiations succeeded, all would be well; if not, they planned to use force to compel the King of Chu to agree. Yet, after selecting his team, he still lacked one person.
At that moment, someone stood up and said to Lord Pingyuan: "My lord, I believe I meet the qualifications to go."
Lord Pingyuan, not recognizing him, asked, "What is your name, and how long have you been in my service?"
The retainer replied, "I am Mao Sui. I've been here for three years."
Lord Pingyuan said, "A man of talent is like a awl in a pouch—it quickly reveals its point. You've been in my service so long, yet I've never heard anyone speak well of you. Clearly, your abilities are ordinary. This mission is of great importance—I think it's best you stay behind."
Mao Sui responded, "It is precisely because you have never placed the awl in the pouch that its point has not shown." Impressed by Mao Sui’s bold words and unable to find a better candidate, Lord Pingyuan decided to let him join the mission.
Upon arriving in Chu, the King of Chu indeed showed no intention of forming an alliance against Qin. All the retainers were at a loss, when suddenly Mao Sui stepped forward calmly, drawing his sword. He approached Lord Pingyuan and the King of Chu. The king ordered him to retreat, but Mao Sui, hand on his sword, said: "You need not rely on your numbers to intimidate me. I am only ten paces from you, and my lord stands here—why are you so angry?"
Seeing Mao Sui holding a sword, the king softened his tone and said, "Well then, I'd like to hear your wise opinion!" Mao Sui then gave a detailed explanation of how an alliance with Zhao would bring countless benefits and no harm to Chu. Convinced, the King of Chu immediately formed a blood oath alliance with Lord Pingyuan, and dispatched Lord Chunshen (Huang Xie) as commander-in-chief, leading an army of 80,000 troops in a grand march to relieve Zhao. As a result, Mao Sui earned the respect of Lord Pingyuan and the other retainers and became instantly famous.