成唯識論述記 2.907

2.907

述曰：下別徵，於中有二：初空理非因難；後起心非淨難。此即初也。此中空理，即是真如，空非心因，常非種子故。彼若救言：常為種子，於理何妨。

The Commentary states: Below he separately examines them, within which there are two parts: first, challenging that the principle of emptiness is not a cause; second, challenging that the arising mind is not pure. This is the first. Here, 'the principle of emptiness' is tathatā. Emptiness is not the cause of mind, because what is permanent cannot be a seed. If they defend their view by saying: 'It is permanent and serves as a seed; what harm is there in reason?'—