Vishnupurana 1.19.30

1.19.30

kathaṃ mantri ṣvamātyeṣu bāhyoṣvābhyantareṣu ca /
cāreṣu pauravargeṣu śaṅkiteṣvitareṣu ca //

When the devices of Samvara were all frustrated, and the blighting wind had perished, the prudent prince repaired to the residence of his preceptor. His teacher instructed him daily in the science of polity, as essential to the administration of government, and invented by Uśanas for the benefit of kings; and when he thought that the modest prince was well grounded in the principles of the science, he told the king that Prahláda was thoroughly conversant with the rules of government as laid down by the descendant of Bhrigu. Hirańyakaśipu therefore summoned the prince to his presence, and desired him to repeat what he had learned; how a king should conduct himself towards friends or foes; what measures he should adopt at the three periods (of advance, retrogression, or stagnation); how he should treat his councillors, his ministers, the officers of his government and of his household, his emissaries, his subjects, those of doubtful allegiance, and his foes; with whom should he contract alliance; with whom engage in war; what sort of fortress he should construct; how forest and mountain tribes should be reduced;