दुर्गाभावे च कोशः परेषाम् ॥ कZ_०८.१.३९ ॥
durgābhāve ca kośaḥ pareṣām
आणि दुर्ग नसल्यास कोश इतरांच्या (शत्रूंच्या) हाती पडतो।
They show a trade-off: treasury is portable (enabling retreat), yet also needs fortified protection; forts secure wealth, but wealth enables mobility and continued resistance.