《宋书·志·卷十二》
这都是来源于选伐与上行相应，土是由火产生的，秦代与水行相应，水足由金产生的，这样汉就以土为赤帝子，秦就以水为白帝子了。
盖由汉是土德，土生乎火，秦是水德，水生乎金，斯则汉以土为赤帝子，秦以水德为白帝子也。
This is all derived from the theory that Suifa corresponds with the rising sun; it is said that earth is produced by fire and that the Qin Dynasty corresponded with water, and that water is produced by gold, so the Han Dynasty was said to be the "son of the Red Emperor" and the Qin Dynasty the "son of the White Emperor."