大乘百法明門論疏 2.9

2.9

The explanation is: "Although these two factors are not subsumed under the five faculties when compared to smṛti, samādhi, and prajñā, their function as hindrances is somewhat lighter; yet when compared to the sarvatragas, they are still grave. Therefore, the Yogācārabhūmi, because these two factors function gravely as hindrances, admits them into the upakleśas."