In Buddhist translated literature, the Chinese expression bù rǎn yú yù 不染於欲 (not attached to desires) is apparently used as variant of the passive construction bù wéi yù suǒ rǎn 不為欲所染 (not tainted by desires) to translate the same Sanskrit source expression na lipyate kāmaiḥ (not being smeared by desires). An Indic parallel closer to bù rǎn yú yù 不染於欲, namely na lippati kāmesu (not being attached to desires), is found in Pāli and in some Hybrid sources. This paper argues that the Sanskrit and Pāli forms can be traced back to a common archetype akin to the Pāli form and that the -ya-present lipyate was originally used as a class IV intransitive present. Owing to use of the historical instrumental suffix -ehi as a generalised oblique plural ending in Middle Indo-Aryan, the form lipyate kāmehi (< *lipyate kāmeṣu) was eventually reanalysed as a present passive. The two variants found in Chinese translations bear witness to the semantic and grammatical ambiguity underlying the Indic source expression.