首楞嚴義疏注經 8.15

8.15

皆依食住者，食以資益諸根大種，心、心所法能生喜樂，相續執持，故有四種。段謂分段，以欲界香、味、觸三正消變時有資益義，乃名為食。觸食謂根、境、識三和合，能引意識相應觸起，觸對前境，能生喜樂，資益諸根及心、心所故。思食謂意識相應，思與欲俱轉，於可意境希望偏勝，有資益義故。識食謂第八識由前三食緣助勢力，令此第八體有增勝，故能執持諸根大種，能與諸法為長養因。有攝益義，故名為食，如四食章。

Regarding 'all abide relying on food': food nourishes and benefits the faculties and great elements, and the mind and mental factors can generate joy and happiness, maintaining and sustaining them in continuity; hence there are four kinds. 'Mouthfuls' means fragmentary portions; in the desire realm, when the three of fragrance, taste, and tangibility are being properly digested and transformed, there is the meaning of nourishing and benefiting, so it is called food. 'Food by contact' means the harmony of faculty, object, and consciousness can induce contact associated with the mental consciousness to arise; contacting the sensory realm before it, it can produce joy and happiness, nourishing and benefiting the faculties as well as the mind and mental factors. 'Food by thought' means that associated with the mental consciousness, thought and desire operate together, having a predominant hope for agreeable realms, which has the meaning of nourishing and benefiting. 'Food by consciousness' means the eighth consciousness, aided by the power of the conditions of the preceding three foods, causes this eighth substance to increase and excel, so that it can maintain the faculties and great elements, and serve as the nourishing cause for all dharmas. Having the meaning of sustaining and benefiting, it is called food, as in the chapter on the four foods.