During the Warring States period, Lord Xinling, born Wuji, was the younger brother of King Anxi of Wei. Known for his benevolence and respect for talent, he attracted many capable men to his service.
In 257 BCE, during the reign of King Anxi of Wei, King Zhao of Qin crushed Zhao's 400,000-strong army at Changping and then besieged Handan, Zhao's capital. Lord Pingyuan of Zhao, whose wife was Lord Xinling's sister, sent urgent pleas to both King Anxi and Lord Xinling for aid. King Anxi initially dispatched the veteran general Jin Bi with 100,000 troops to rescue Zhao, but when Qin's envoys threatened, "Any state that dares to aid Zhao will face our army's full wrath once we conquer it," the terrified king ordered his forces to halt at the border, nominally supporting Zhao while actually waiting to see which way the wind blew.
One after another, Lord Pingyuan's envoys arrived in Daliang, the capital of Wei, and reproached Lord Xinling, saying, "I allied with Wei through marriage because I admired your noble character and your ability to help others in distress. Now Handan is on the verge of falling to Qin—where is your help? And even if you despise me, Zhao Sheng, do you not pity your own sister?"
Lord Xinling was burning with anxiety, trying every possible way to persuade the King of Wei to rescue Zhao, but the king refused to listen. In utter desperation, he finally heeded the advice of Hou Ying, a reclusive sage guarding the Yimen Gate in Daliang. Hou Ying suggested, "Have the king's favorite concubine, Ruji, steal the military tally from the king's bedchamber." Risking his own life, Lord Xinling then used the forged royal order to seize command of the army, leading the troops to lift the siege on Zhao and thus saving the state of Zhao from destruction.
Later, the idiom "Ji Ren Zhi Kun" came to describe being eager to help others solve their difficulties.
Source: *Records of the Grand Historian*, "Biography of Lord Xinling"
Meaning of the Idiom: Later, the Chinese idiom "急人之困" came to describe being eager to help others solve their difficulties.