大方廣佛華嚴經隨疏演義鈔 19.52

19.52

疏「即東方青帝等類」者，此主五方有五帝。東方甲乙木，其色青故，東方為青帝。南方丙丁火，其色赤，為赤帝。西方庚辛金，其色白，為白帝。北方壬癸水，其色黑，為黑帝。中央戊己土，其色黃，為黃帝。若十二神，即一方有三故，故成十二。《大集經》說：十二獸皆是大菩薩示迹為之，廣如彼說。

Regarding the Commentary's words, "That is, the Green Thearch of the East and his kind": these govern the five directions where there are five thearchs. The East is jiǎ and yǐ wood; its color is green, hence the East is the Green Thearch. The South is bǐng and dīng fire; its color is red, making the Red Thearch. The West is gēng and xīn metal; its color is white, making the White Thearch. The North is rén and guǐ water; its color is black, making the Black Thearch. The Center is wù and jǐ earth; its color is yellow, making the Yellow Thearch. As for the twelve spirits, each direction has three, thus making twelve. The Mahāsaṃnipāta-sūtra explains that the twelve animals are all manifested traces of great bodhisattvas, as expounded at length there.