俱舍論頌疏論本 20.62

20.62

同無記內門，定地故合一者，明上二界合為有漏也。一同無記性、二同內門轉（緣定及身，名內門轉也）、三同是定地，由此三義，二界隨眠合為一漏。

"Because they share in being non-defined, internal, and in the stage of concentration, they are united as one" clarifies that the upper two realms are combined into the effluent of existence: first, they share the nature of being non-defined; second, they share an internal activity (taking concentration and the body as their objects is called operating internally); third, they share in belonging to the stage of concentration. Due to these three meanings, the latent defilements of the two realms are united into a single effluent.