成唯識論述記 6.104

6.104

述曰：正理師等，亂心等時亦有定起，但相微隱，相難知者。今詰彼曰：「應說誠言」，誠謂誠諦，虛言說有，理未可通。應緣實言，令我知有。

The Commentary states: Masters of the Nyāyānusāra and others say that at the time of a disturbed mind, etc., concentration also arises, but its marks are subtle, hidden, and difficult to know. Now we cross-examine them: 'They should state their true reasoning.' 'True' means authentic and real; stating its existence in empty words cannot be established by principle. They must provide real, factual words so that I may know it exists.