Mbh 12.66.2b

In consequence of the protection of all creatures as also of the proper protection of his own kingdom, a king earns the merit of as many sacrifices as the number of creatures protected, and accordingly attains to the object of the Sannyasa mode of life. Study of the Vedas every day, forgiveness, and worship of preceptors, and services rendered to one's own teacher, lead to the attainment of the object of Brahmacharya. That king who silently recites his mantras every day and who always worships the gods according to the ordinance, attains, O tiger among men, to the object of the Garhasthya mode of life. That king who engages in battle with the resolve of protecting his kingdom or meeting with death, attains to the object of the Vanaprastha mode of life. That king who gives unto persons leading a Vanaprastha mode of life and unto Brahmanas versed in the three Vedas attains to the object of the Vanaprastha mode of life. That king who displays compassion towards all creatures and abstains entirely from cruelty, attains to the objects of all the modes of life. That king, O Yudhishthira, who shows compassion to the young and the old, O son of Kunti, under every circumstance, attains to the objects of every mode of life. That king, O perpetuator of Kuru's race, who affords relief to all oppressed people that seek his protection, attains to the object of the Garhasthya mode of life. That king who protects all creatures mobile and immobile, and honours them as they deserve, attains to the object of the Garhasthya mode of life. Bestowing favours and inflicting punishments upon the wives and brothers, elder and younger, and upon their sons and grandsons, are the domestic duties of a king and these constitute his best penances. By honouring those that are righteous and deserving of worship and protecting those that have (by their penances) acquired knowledge of self, a king, O tiger among men, attains to the object of the Garhasthya mode of life.