Mbh 12.71.2c

Thou shouldst give them wealth to the best of thy power and as they deserve and protect them, comforting them on all occasions. By conducting thyself in this way, thou mayst acquire such regions hereafter as are most difficult of acquisition. Adopting such virtuous behaviour, do thou protect thy subjects. Thou mayst then obtain, O delighter of the Kurus, fame that is everlasting, high, and pure. Protect thy subjects righteously, O son of Pandu, for no regret or pain will then be thine. Protection of the subject is the highest duty of the king, since compassion to all creatures and protecting them from injury has been said to be the highest merit. Persons conversant with duties regard that to be the highest merit of the king, when, engaged in protecting all creatures, the king displays compassion towards them. The sin a king incurs by neglecting for a single day to protect his subjects from fear is such that he does not attain to end of his sufferings (for it) in hell till after a thousand years. The merit a king earns by protecting his subjects righteously for a single day is such that he enjoys its reward in heaven for ten thousand years. All those regions that are acquired by persons leading duly the Garhasthya, the Brahmacharya, and the Vanaprastha modes of life, are soon acquired by a king by only protecting his subjects righteously. Do thou, O son of Kunti, observe with great care this duty (of protection). Thou shalt then obtain the reward of righteousness and no grief and pain will be thine. Thou shalt, O son of Pandu, obtain great prosperity in heaven. Merit like this is impossible to be acquired by persons that are not kings. A person, therefore, who is a king, and no other, can succeed in earning such reward of virtue. Possessed of intelligence, thou hast obtained a kingdom. Do thou protect thy subjects righteously. Gratify Indra with offerings of Soma and the friends and well-wishers with the objects of their wishes."'"