For example, what is "purple light shining high"?

Ziweixing is one of the three walls (Taiweiyuan, Ziweiyuan and Tianshiyuan). Wei Zi is also listed as one of the Four Emperors by Taoism. It is said that Wei Zi Zhongtian was the emperor of the Arctic. In Taoism, he helped the Jade Emperor manage the natural latitude, the sun, the moon, the stars and the four seasons, so he was worshipped by emperors of all dynasties. Wei Zi's holding high the lamp symbolizes exorcism, welcoming blessings and praying for blessings.