Mbh 5.132.2a

“Kunti said, ‘O Kesava, say unto king Yudhishthira of virtuous soul these words, “Thy virtue, O son, is decreasing greatly. Do not act vainly. O king, like a reader of the Vedas incapable of catching their real meaning, and, therefore, truly unlearned. Thy understanding, affected by only the words of the Vedas, vieweth virtue alone. Cast thy eyes on the duties of thy own order, as ordained by the Self-create. For all ruthless deeds and for the protection of the people, from his (Brahmana’s) arms was created the Kshatriya, who is to depend upon the prowess of his own arms. Listen, an instance is cited in this connection, that hath been heard by me from the aged. In days of yore, Vaisravana, having been gratified, made a gift of this Earth to the royal sage Muchukunda. The latter without accepting the gift, said, ‘I desire to enjoy that sovereignty which is won by prowess of arms.’ At this, Vaisravana was highly delighted and filled with wonder. King Muchukunda then, fully observing the duties of the Kshatriya order ruled this earth, having conquered it by the prowess of his arms. Then again, a sixth part of the virtue, practised by subjects well-protected by the king, is obtained, O Bharata, by the king. The virtue again that the king himself practiseth conferreth godhead on him, while if he perpetrateth sin, he goeth to hell. The penal code properly applied by the ruler, maketh the four orders adhere to their respective duties, and leadeth to an acquisition (by the ruler himself) of virtue (profit, and salvation). When the king properly abideth by the penal code, without making any portion of it a dead letter, then that best of periods called the Krita Yuga setteth in. Let not this doubt be thine, viz., whether the era is the cause of the king, or the king the cause of the era, for (know this to be certain that) the king is the cause of the era. It is the king that createth the Krita, the Treta, or the Dwapara age.