俱舍論疏 28.82

28.82

論「立第四名至名非非想」，立第四名。由想昧劣，無明勝想，得非想名；有昧劣想，名非非想也。

The Śāstra says: "Establishing the fourth name... [it is called neither-perception-nor-non-perception]," which establishes the fourth name. Because its perception is dim and weak, lacking clear and prominent perception, it gets the name "neither perception"; because a dim and weak perception still exists, it is named "nor non-perception."