What are the stories behind Grain Rain in the 24 solar terms?

Among the people, there is a story circulating in Guanzhong, Shaanxi:

According to legend, more than 4,000 years ago, Huangdi in Xuanyuan urgently needed a historian in charge of historical materials.

One day, the Yellow Emperor discovered Cang Xie with both ability and political integrity and appointed Cang Xie as a historian. He remembered the important events of the country clearly by tying knots, which was very appreciated by the Yellow Emperor. Later, the knot notes became more and more backward.

Once, Cang Xie went out hunting with a hunter. The hunter pointed to the traces of various wild animals left on the ground and told the whereabouts of wild animals. Cang Xie was deeply inspired: "A footprint represents a thing!" After returning home, Cang Xie packed up and went out for a trip. He climbed mountains and waded in water, was not ashamed to ask questions, and expressed everything he saw according to its characteristics.

Pictographic by class, original text. Because of his contribution to word-making, he touched the Emperor of Heaven. At that time, there was a famine in the world, so he ordered the heavenly soldiers to open the granary of the Heavenly Palace, and millet was planted, and all the people in the world were saved.

After Cang Xie's death, people buried him in his hometown-north of Shiguan Town, Baishui County. There is a couplet engraved at the entrance of the tomb: "The rain millet feels that the Emperor of Heaven was in those days, and the same language matches the bridge Lingyong." People set the day of offering sacrifices to Cang Xie as the day of Grain Rain, which is now "Grain Rain Festival".

Nowadays, every Grain Rain Festival, there is a temple fair in Shiguan Town, Baishui County to worship Cang Xie.