Yong-le: Year 5, Month 7, Day 26
28 Aug 1407
The Jiao-zhi Provincial Administration Commission memorialized: "The yi people of Annam venerate the law of the Buddha (尚浮屠法) but do not know how to worship or sacrifice to the spirits. We should establish altars for sacrifice to the spirits of the wind, clouds, thunder and rain, the mountains and rivers and the soil and grain, so that the people become familiar with the way to express gratitude to the spirits through sacrifices (祈報之道)." This was approved.
Zhong-yang Yan-jiu yuan Ming Shi-lu, volume 11, page 978