大乘起信論義記 1.18

1.18

問：若諸無姓亦當成佛，何得說有無姓有情？答：論有二釋，故《佛性論》及《寶性論》同為謗大乘人，依無量時故作是說，非謂究竟無清淨性。《佛性論》第二卷中，判說無佛性是不了教故也。准此當知，永無種姓非盡理說。《楞伽》文說可知。

Question: If those of no gotra will also become Buddhas, why is it taught that there are sentient beings of no gotra? Answer: Śāstras offer two explanations; hence both the Buddhadhātuśāstra and the Ratnagotravibhāga explain that this was stated in reference to people who slander the Mahāyāna, on account of an immeasurable period of time, and does not mean that they ultimately lack the pure nature. In the second fascicle of the Buddhadhātuśāstra, it determines that teaching the absence of buddha-nature is an incomplete teaching (neyārtha). Based on this, one should know that an eternal absence of gotra is not the ultimate explanation of the principle. This can be known from the text of the Laṅkāvatārasūtra.