俱舍論記 23.3

23.3

「如是已說至治倒故唯四」者，此下第三明四念住。就中，一明別相念住、二明總相念住。此即明別相念住，七加行中第二加行也。結前問起。如是已說不淨息念入、修二門，由此二門心便得定。心得定已，復何所修？就頌答中，初頌標名總舉，次兩句出體，次一句明次第，後一句明唯四種。

Regarding "Thus has been explained ... Because they remedy distortions, there are only four": from this point down is the third section, explaining the four foundations of mindfulness (smṛtyupasthāna). Within this, there are two parts: first, explaining the foundations of mindfulness with specific characteristics; second, explaining the foundations of mindfulness with general characteristics. Here it explains the foundations of mindfulness with specific characteristics, which is the second preparatory application (prayoga) among the seven preparatory applications. It sums up what precedes and introduces the query: Thus the two approaches of impurity and mindfulness of breathing, entering and cultivating, have been explained, by means of which the mind attains samādhi. Having attained samādhi, what else should one cultivate? In the verses that give the answer, the first verse indicates the name and presents the whole topic in general; the next two lines bring out their essence; the next line explains their sequence; and the final line explains why there are only four.