In the 6th year of the reign of Duke Ai of Lu state, Confucius was invited to Chu state to take a government position. Ministers of Chen state and Cai state were afraid that Chu would put Confucius in important positions, which might threaten the two states. Therefore, both states dispatched troops to surround Confucius and his disciples in somewhere between Chen and Cai. Seven days later, they had ran out of provisions. The disciples were very hungry and exhausted, but Confucius was still lecturing and playing the qin. Later, he sent Zigong to Chu to ask for help and they were finally rescued.