Magu, the daughter of the fierce general Ma Qiu, was deeply compassionate. Her father forced workers to build a city day and night, only allowing them rest at cockcrow. Magu, feeling pity for the laborers, cleverly imitated a cockcrow, prompting other chickens to follow suit, thus granting the exhausted workers an early respite.

When Ma Qiu discovered this, he was enraged and pursued his daughter into the mountains, intending to punish her. Magu fled and gained immortality.

Legend further elaborates that Ma Qiu, in his fury, set fire to the mountain to kill Magu. Coincidentally, the Queen Mother of the West (Wangmu) was passing by. Seeing the flames, she quickly brought forth a heavy rain to extinguish the fire. Upon learning the full story, Wangmu greatly admired Magu's kindness and compassion for the people. She took Magu as her disciple and brought her to Magu Mountain in Nancheng County for cultivation.

There, Magu used the water from thirteen clear springs to brew a special spirit mushroom wine (Lingzhi wine). After thirteen years, the wine was perfected, and Magu herself achieved immortal status. It happened to be the Queen Mother of the West's birthday, so Magu brought her precious spirit wine to Yao Tai (the legendary abode of immortals) to offer her birthday felicitations.

The Queen Mother was delighted and bestowed upon Magu the title of "Xū Jì Chōng Yīng Zhēn Rén" (虚寂冲应真人). The imagery of "Magu Offering Longevity" thus originated from this tale and is widely used as a symbol of good fortune and birthday blessings.