俱舍論記 29.32

29.32

「此四無量至唯不成喜故」者，釋第十二句。此四無量人中現起，非於餘處。此即現起分別。隨得一時，必成慈、悲及捨三種。生第三定等，唯不成喜故。此即成就分別。（此四無量，廣如《婆沙》八十一八十二解）。

Regarding "these four immeasurables, up to: because only joy is not accomplished": this explains the twelfth line. These four immeasurables manifest among human beings, not elsewhere; this is the distinction according to manifestation. Whenever any one [of them] is attained at a given time, one necessarily accomplishes three kinds: benevolence, compassion, and equanimity. For one born in the third dhyāna and above, only joy is not accomplished; this is the distinction according to accomplishment. (These four immeasurables are explained in detail as in fascicles 81 and 82 of the Mahāvibhāṣā).