瑜伽論記 2.337

2.337

婆羅門是白淨色類者，善勝種非白色也。得清淨者，修行潔戒可得淨故。腹所生者，彼執大梵腹臍臍中生蓮華，華生梵天，梵天口生婆羅門，臂生剎利，髀生吠舍，跟生首陀，故婆羅門是最勝姓。

Regarding 'Brāhmaṇas are a pure white class': this refers to an auspicious and superior lineage, not a white physical colour. 'Attaining purity': because through practicing pure precepts, purity can be attained. Regarding 'born from the belly': they hold that a lotus flower arose from the belly and navel of Great Brahmā, from which Brahmadeva was born; Brahmadeva's mouth produced the brāhmaṇas, his arms produced the kṣatriyas, his thighs produced the vaiśyas, and his heels produced the śūdras; therefore, the brāhmaṇa is the most supreme caste.