俱舍論頌疏論本 8.13

8.13

依同分及命，令心等相續者，明無色界所依也。欲、色有身，心依身而轉。無色無身，心依同分及命根轉。

"Relying upon generic similarity and life-force, it causes the mind and so forth to continue": this clarifies what is relied upon in the formless realm. The desire and form realms have a body, so the mind operates in reliance upon the body. The formless realm has no body, so the mind operates in reliance upon generic similarity (nikāyasabhāga) and the life-faculty (jīvitendriya).