【Source】Zuo Qiuming, "Zuo's Commentary on the Spring and Autumn Annals · Chenggong's Eighth Year" (Spring and Autumn period).
【Explanation】"Cong" means to follow; "Shan" refers to good or correct opinions; "Ru Liu" means like a flowing stream. The phrase describes accepting others' correct suggestions quickly and naturally, as effortlessly as water flows. It means being eager to accept sound advice and willing to heed well-intentioned counsel.
【Historical Anecdote】
Luan Shu was a senior minister of the State of Jin during the Spring and Autumn period. Due to his repeated military achievements, he was promoted to commander-in-chief of the central army. In 585 BC, the State of Chu sent tens of thousands of elite troops to attack Zheng. Unable to resist, Zheng appealed to Jin for help. Duke Jing of Jin dispatched Luan Shu to lead the relief force. As soon as Luan Shu's army entered Zheng's territory, they encountered Chu's forces. Seeing the formidable Jin army, the Chu troops withdrew and returned home.
Unwilling to retreat immediately, Luan Shu decided to attack Cai, an ally of Chu. The small state of Cai, under Jin's assault, quickly sent envoys to Chu for help. Although Chu had no desire for direct confrontation with Jin, Cai's plea for aid made battle unavoidable. Thus, the King of Chu sent Prince Shen and Prince Cheng to lead troops in Cai's defense.
Jin generals Zhao Tong and Zhao Kuo requested permission from Luan Shu to engage the approaching Chu relief forces, and Luan Shu agreed. At this point, Luan Shu's subordinates—Zhi Zhuangzi, Fan Wenzu, and Han Xianzi—advised: "The Chu army had already retreated but has now turned back, meaning they must be well-prepared. We must not be careless. Even if we win, defeating Chu's army is nothing to celebrate; but if we lose, it will bring great shame. Weighing the pros and cons, it is better not to fight. Let us withdraw and return home." Luan Shu found their reasoning sound and ordered preparations for retreat.
However, many in the army still wanted to fight and achieve victory over Chu. Upon hearing Luan Shu's decision to withdraw, they said to him: "In fact, wise men and the majority often think alike. As long as one acts with sincerity, success can be achieved. Why not follow the majority's opinion? As commander, you have eleven advisors, of whom only three oppose battle. Clearly, the majority favors fighting. Why not act according to the majority view?" Luan Shu replied: "Only correct opinions truly represent the majority. Zhi Zhuangzi and the other two are virtuous men of Jin. Their advice is sound and thus represents the will of the majority. Therefore, I will follow their counsel." With that, Luan Shu ordered the army to withdraw.
Two years later, Luan Shu led his troops to conquer Cai and then planned to attack Chu. However, Zhi Zhuangzi, Fan Wenzu, Han Xianzi, and others analyzed the current situation and advised that they should not attack Chu immediately, but instead invade the state of Shen. Luan Shu found their suggestion reasonable and acted accordingly. He attacked Shen and ultimately achieved victory.
Luan Shu's willingness to heed his subordinates' good advice earned him praise: "He can readily accept sound and correct advice, just as swiftly as flowing water."