yato viśeṣaṇoparaktaṃ viśeṣyaṃ grāhayad viśeṣaṇam ucyate anyathā viśeṣaṇasyānupapannatvād iti bhāvaḥ
Since [something] is called a qualifier [only] when it causes the apprehension of a qualificand that is tinged by [that] qualifier, otherwise the status of being a qualifier would not be possible - this is the meaning.