Tu Gu Hun in ancient times is now the Song Pan area of Qinghai and Sichuan Provinces.

A'cai, chief of Tu Gu Hun, had 20 sons. One day A'cai said to them: "Each one of you bring me an arrow."

Then, he broke the arrows one by one and threw them on the ground.

After a while, A'cai said to Mu Liyan, his half-brother by the same mother: "Bring an arrow and break it."

Mu Liyan broke the arrow without any effort. "Bring 19 arrows and break them together," demanded A'cai again.

But this time Mu Liyan couldn't make it despite all his efforts.

Thereupon, A'cai said meaningfully: "Do you know the reason behind? A single arrow can be easily broken, but assembled together, the arrows will be hard to destroy. As long as you work in full cooperation and with unity of purpose, our throne will be passed down from generation to generation."

古时候的吐谷浑，就是现在的青海及四川的松潘一带。

吐谷浑的首领阿豺有二十个儿子。一天，阿豺对他的儿子了说：“你们每人给我拿一支箭来。”

然后，他把拿来的箭一一折断，扔在地下。

过了一会儿，阿豺又对他的同母弟弟慕利延说：“你拿一支箭来把它折断。”

慕利延毫不费力地把箭折断了。阿豺又说：“你再拿十九支箭来把它们一起折断。”

这时候，慕利延竭尽全力，怎么也折不断。

于是，阿豺意味深长地说：“你们知道其中的道理吗?单独一支容易折断，聚集在一起就很难被摧毁。只要你们同心协力，我们的江山就可以一代一代地传下去。”