成唯識論述記 7.74

7.74

述曰：下以喻成。五十二說：內法種子，簡麥、豆等，其體實有。彼言世俗，但所對別，非言世俗，一切定假。不爾，內種即假有失。假法如無，非因緣故，非是調然離識有體，如心、心所，名為世俗，體仍非假，世親《攝論》亦有此說，假非因故。

The Commentary states: Below, it is established by an analogy. Fascicle 52 states: seeds of internal dharmas—as distinguished from wheat, beans, and the like—are real in substance. Its use of the word "conventional" there is merely due to a difference in contrast; it does not mean that whatever is called "conventional" is definitely provisional in all cases. If it were not so, internal seeds would suffer the fault of being provisionally existent. Provisional dharmas are like non-existents and are not cause-and-condition (hetu-pratyaya); they do not distinctly possess substance apart from consciousness, yet like mind and mental factors they are called conventional, while their substance remains non-provisional. Vasubandhu's Mahāyānasaṃgraha-bhāṣya also contains this explanation, because what is provisional cannot be a cause.