俱舍論頌疏論本 11.75

11.75

色界諸天中無晝夜別，但約劫數知壽短長，彼壽短長與身量等，謂若身量半踰繕那，壽量半劫；若彼身量一踰繕那，壽量一劫；乃至身量長萬六千踰繕那，壽量亦同萬六千劫。

Among the gods of the form realm there is no distinction of day and night; they understand the length of life only in terms of the number of kalpas. The length of their life equals their body size: that is, if the body size is half a yojana, the lifespan is half a kalpa; if their body size is one yojana, the lifespan is one kalpa; up to a body size of sixteen thousand yojanas, where the lifespan likewise is sixteen thousand kalpas.