From
三国志·
蜀志·
诸葛亮传 and Pei Songzhi's citation of
汉晋春秋: during Zhuge Liang's 225 southern campaign he captured the Nanzhong chieftain Meng Huo (
孟获) seven times and released him each time until Meng Huo submitted wholeheartedly. The idiom means using strategy to win an opponent's true submission.