唯識二十論述記 2.166

2.166

Prior to Dignāga, ancient non-Buddhists and Buddhists, both Mahāyāna and Hīnayāna masters, all spoke of three means of cognition: first, direct perception (pratyakṣa); second, inference (anumāna); third, verbal testimony of the sages (śabda-pramāṇa). Now, according to the Sanskrit, it is called āptāgama, translated here as 'authoritative teaching' (āptāgama). The means of cognition of authoritative teaching is not [merely what one] attains, but what the holy ones have spoken, which is called authoritative teaching. Whenever worldly words are unerring, not of two kinds, and worthy of trust, they are all the means of cognition of authoritative teaching, because they accord with ultimate truth and conform to real facts, like the chapter on the eight kinds of speech, the four noble statements, and so forth.