妙法蓮華經玄義 4.5

4.5

行人既內證四禪，欲外修福德，應學四等。此有通修、別修。通修者，《大論》云：「是慈在色界四禪中間得修。」此語則通。別修者，初禪有覺觀分別，修悲則易；喜支修喜易；樂支修慈易；一心支修捨易。復次，初禪修悲易：二禪修喜易：三禪修慈易：四禪修捨易。此則修四無量定之處所也。復次，修時緣前人離苦得樂，歡喜平等之相而入定。發時，內得喜樂平等之法，外見前人離苦得樂；或內得外不見、或外見內不得，分別邪正（云云）。

Once the practitioner has internally realized the four dhyānas and wishes externally to cultivate merit and virtue, they should learn the four immeasurables. This has general cultivation and specific cultivation. For general cultivation, the Mahāprajñāpāramitopadeśa says: 'This loving-kindness can be cultivated in the interval of the four dhyānas of the form realm.' This statement is general. For specific cultivation, in the first dhyāna there is the discrimination of initial and sustained thought, so cultivating compassion is easy; with the factor of joy, cultivating sympathetic joy is easy; with the factor of pleasure, cultivating loving-kindness is easy; with the factor of one-pointedness of mind, cultivating equanimity is easy. Furthermore, in the first dhyāna cultivating compassion is easy; in the second dhyāna cultivating sympathetic joy is easy; in the third dhyāna cultivating loving-kindness is easy; in the fourth dhyāna cultivating equanimity is easy. These are the locations for cultivating the four immeasurable concentrations. Furthermore, at the time of cultivation, one conditions upon the other person's characteristics of departing from suffering and obtaining happiness, rejoicing, and equanimity, and enters concentration. When it is activated, internally one attains the dharmas of joy, pleasure, and equanimity, and externally one sees the other person departing from suffering and obtaining happiness; or internally one attains it while externally not seeing it, or externally one sees it while internally not attaining it, distinguishing between the deviant and the correct, and so forth.