楞伽阿跋多羅寶經註解 1.601

1.601

此斥外道無常性所以，難其無果，以其因非正因故，復對因反復斥之。言異相因者，非我自因之相也。彼言常者，非自作正因實相之力所成之常，乃非常計常之常，豈顯常性之果哉？又復外道所計常不思議，乃言「世間所作之法有已還無，悉是無常，性非性即有無也。」作是見已，妄計神我以為常不思議，故云「思量計常」。

This refutes the reason why the tīrthikas have an impermanent nature and challenges their lack of fruit. Because their cause is not a correct cause, he further refutes it back and forth with respect to the cause. Saying 'their cause has a different lakṣaṇa' means it is not the lakṣaṇa of one's own cause. Their asserting permanence is not the permanence established by the power of the true lakṣaṇa of a correct cause produced by oneself; rather, it is a permanence constructed as permanent upon what is impermanent. How could it reveal the fruit of an eternal nature? Moreover, the permanence and incomprehensibility constructed by the tīrthikas merely says: 'Dharmas produced in the world, having existed, revert to nonexistence; all are impermanent. Nature and non-nature are simply existence and nonexistence.' Having formed this view, they falsely construct a spiritual self as permanent and incomprehensible; hence it is said that they 'mentally deliberate and construct permanence.'