धात्वर्थं बाधते कश्चित्कश्चित्तमनुवर्तते तम् ।
एव विशिनष्ट्यन्योऽनर्थकोऽन्यः प्रयुज्यते ॥
dhātv-arthaṁ bādhate kaścit kaścit tam anuvartate tam |
eva viśinaṣṭy anyo’narthako’nyaḥ prayujyate ||
(Prayuktākhyāta-mañjarī: 3.4.12)
“Some [prefixes] block the meaning of the verbal root, some follow it, others distinguish it, and others are used without meaning [i.e., to fill out the meter in a verse].”