俱舍論疏 4.128

4.128

論「別於無記至謂尋與伺」，第四釋有覆無記相應品也。性是染污，能有隱覆，名為有覆。體非巧便，無果記故，名為無記。

The Śāstra says: "Separately, in the indeterminate […] namely, vitarka and vicāra." This fourthly explains the mental category associated with the obstructed-indeterminate. Its nature is defiled and capable of veiling, hence it is called obstructed. Its essence is unskilful and lacks a recorded maturation of fruit, hence it is called indeterminate.