俱舍論疏 4.130

4.130

論「於餘無記至并不定尋伺」，此第五釋無覆無記。體非染污，不障聖道，無果記故，名無覆無記。

The Śāstra says: "In the remaining indeterminate […] together with the unfixed vitarka and vicāra." This fifthly explains the unobstructed-indeterminate. Its essence is non-defiled, it does not obstruct the noble path, and it lacks a recorded maturation of fruit; hence it is called unobstructed-indeterminate.