(In 594 BCE) during autumn, in the 7th lunar month, Duke Huan of Qin led an expedition against Jin, pitching camp at Fushi (present day Dali County). On (the zodiac day of) YangWaterHorse, Marquis of Jin had been training his army at Ji (south of present day Jishan County), so that he could seize the lands of the Di people. After installing Marquis of Li there, Marquis of Jin returned home (in order to mount a defense against the Qin). However, by the time Marquis of Jin arrived at Luo (present day Luoyang), Wei Ke (of Jin) had already defeated the Qin army at Fushi, taking a powerful man from Qin, named Du Hui, as his prisoner. As it turns out, (Wei Ke's father) Wei Wuzi had a favorite concubine, who was childless. When Wuzi was ill, he instructed Ke, saying that Ke should marry her off. Later, when Wuzi had become gravely ill, Wuzi said that she must be buried alive in his grave. After his father's death, Ke married her off, saying, "My father was gravely ill, so his thinking was muddled; I will abide by the instructions he gave me when he was still in control of his faculties." Later on, during the battle of Fushi, Ke saw an old man making a rope out of grass in order to block Du Hui’s path. Du Hui tripped on the rope and fell. As a result, Ke was able to capture him. That night, Ke had a dream about the old man, who said to him, "I am the father of the woman that you married off. You abided by the instructions that your father gave you when he was still in control of his faculties. I (did) this in order to repay you." (Wiktionary translation)