成唯識論述記 3.385

3.385

述曰：此第二因。又此觸數定是實有，四食性故，如餘三食。段食香、味、觸既許是實，故以為喻。四大觸實故，於理無違。或應心所亦通於下，簡略便盡。

The Commentary states: This is the second reason. Furthermore, this mental factor of contact is definitely real, because it is of the nature of the four nutriments, like the other three nutriments. Since the odor, taste, and tangible of material nutriment (kavaḍīkārāhāra) are accepted as real, they are used as an example. Because the tangibles of the four great elements are real, there is no contradiction in principle. Alternatively, 'mental factor' should also apply below, so that the qualification is complete.