Matsya Purana 226.8

226.8

pratāpayuktastejasvī nityaṃ syāt sarvakarmasu.
duṣṭasāmanta hiṃsreṣu rājāgneyavrate sthitaḥ .. 226.7 ..

People are satisfied to look at their king as they are at the sight of the Moon. He is always rigorous and strong to curb the sinners and he should burn as fire does all his enemies who are envious and wicked. This is his Âgneyavrata.—6-7.