You should always gather information through spies in various disguises, whose faithfulness have been tested, who are natives of your kingdom, and who should not be known to your enemies.
चारयेयाश्च सततं चारैरविदितः परैः। परीक्षितैर्बहुविधैः स्वराष्ट्रप्रतिवासिभिः॥