खनिः संग्रामोपकरणानां योनिः द्रव्यवनं दुर्गकर्मणां यानरथयोश्च हस्तिवनं हस्तिनां गवाश्वखरोष्ट्राणां च व्रजः ॥ कZ_०७.१४.२५ ॥
khaniḥ saṃgrāmopakaraṇānāṃ yoniḥ dravyavanaṃ durgakarmaṇāṃ yānarathayośca hastivanaṃ hastināṃ gavāśvakharoṣṭrāṇāṃ ca vrajaḥ
Mines are the source of implements of war; resource-forests supply materials for fortification works and for vehicles and chariots; elephant-forests are the source of elephants; and herds (vraja) are the source of cattle, horses, donkeys, and camels.
They are state-controlled inputs for defense and logistics; securing them is equivalent to securing military readiness.