四明十義書 2.81

2.81

故《義例》云：諸色心現時，如金銀隱起。心全金故，收一切隱起。色全金故，亦收一切隱起。故若說唯心，亦論唯色。既皆唯、皆遍，故皆論有於佛性也。

Therefore the Yili states: "When all forms and minds appear, they are like embossments on gold and silver. Because mind is entirely gold, it encompasses all embossments; because form is entirely gold, it likewise encompasses all embossments." Therefore, if one speaks of mind-only, one also discusses form-only. Since both are "only" and both are pervasive, both are discussed as possessing buddha-nature.