俱舍論疏 3.46

3.46

論「生由女男從彼生故」，此意偏說欲界胎、卵生也。此中有難：行、執有用於口、腹，由茲不定，手、足不立根。生中亦有不依男、女根，此亦不定，應非根。

The Śāstra states: "Arising is due to female and male, because one is born from them." The intention here specifically refers to womb-born and egg-born beings in the desire realm. Here there is an objection: Walking and grasping have functions with regard to the mouth and stomach; because these are not invariable, the hands and feet are not established as faculties. In arising, there are also beings that do not depend on the male and female faculties; this too is not invariable, so they should not be faculties.