大乘義章 2.57

2.57

第六約繫不繫辨異。數滅不繫，無為法故。彼得是繫及與不繫，有為法故。得彼八禪等智所滅，名之為繫，得無漏滅，名為不繫。非數不繫，非數無為法故。得唯是繫，有漏法故。無常之滅，通繫不繫，得亦如之，就有漏說名之為繫，就無漏說名為不繫。

Sixth, distinguishing differences in terms of bound and unbound. Cessation through deliberation is unbound, because it is an unconditioned dharma. Its attainment is both bound and unbound, because it is a conditioned dharma. Attaining that which is extinguished by the eight dhyānas and conventional knowledge is termed bound; attaining untainted cessation is termed unbound. Cessation not through deliberation is unbound, because it is the unconditioned dharma of non-deliberation. Its attainment is only bound, because it is a tainted dharma. Impermanent cessation covers both bound and unbound, and its attainment is likewise: spoken of with respect to the tainted, it is termed bound; spoken of with respect to the untainted, it is termed unbound.