俱舍論記 27.36

27.36

「論曰至第三念住」者？釋上句三念住及下一句，初指經說、二別釋三。一緣順境不生歡喜住正念知；二緣違境不生憂戚住正念知；三緣順、違不生歡、戚住正念知。《正理論》云「如前說四，今復說三，可總說言念住有七。今三攝在前四中故，謂在緣外法念住攝。」又《婆沙》三十云「如是三種不共念住，應知亦攝在處非處智力。」廣分別義，如理應思。

On the passage "The commentary says: ... the third application of mindfulness": This explains the upper line on the three applications of mindfulness and the lower line. First, it refers to the sutra's explanation; second, it explains the three individually: 1. Taking an agreeable object, joy does not arise, and one abides in right mindfulness and clear comprehension; 2. Taking a disagreeable object, sadness does not arise, and one abides in right mindfulness and clear comprehension; 3. Taking agreeable and disagreeable objects together, neither joy nor sadness arises, and one abides in right mindfulness and clear comprehension. The Nyāyānusāra says: "Four were spoken of previously, and now three more are spoken of; in summary, one may say that there are seven applications of mindfulness. These three are subsumed under the previous four, meaning they are subsumed under the application of mindfulness that observes external phenomena." Furthermore, the Mahāvibhāṣā, fascicle 30, says: "These three kinds of unshared applications of mindfulness should be known to be also subsumed under the power of knowing the possible and the impossible." The extensive explanation of the meaning should be considered in accordance with principle.