SB 3.3.18

ayājayad dharma-sutam
 aśvamedhais tribhir vibhuḥ
so ’pi kṣmām anujai rakṣan
 reme kṛṣṇam anuvrataḥ
Synonyms: 
ayājayat — made to perform; dharma-sutam — by the son of Dharma (Mahārāja Yudhiṣṭhira); aśvamedhaiḥ — by horse sacrifices; tribhiḥ — three; vibhuḥ — the Supreme Lord; saḥ — Mahārāja Yudhiṣṭhira; api — also; kṣmām — the earth; anujaiḥ — assisted by his younger brothers; rakṣan — protecting; reme — enjoyed; kṛṣṇam — Kṛṣṇa, the Personality of Godhead; anuvrataḥ — constant follower.
Translation: 
The Supreme Lord induced the son of Dharma to perform three horse sacrifices, and Mahārāja Yudhiṣṭhira, constantly following Kṛṣṇa, the Personality of Godhead, protected and enjoyed the earth, assisted by his younger brothers.
Purport: 

Mahārāja Yudhiṣṭhira was the ideal monarchical representative on the earth because he was a constant follower of the Supreme Lord, Śrī Kṛṣṇa. As stated in the Vedas (Īśopaniṣad), the Lord is the proprietor of the entire manifested cosmic creation, which presents a chance for the conditioned souls to revive their eternal relationship with the Lord and thus go back to Godhead, back home. The whole system of the material world is arranged with that program and plan. Anyone who violates the plan is punished by the law of nature, which is acting by the direction of the Supreme Lord. Mahārāja Yudhiṣṭhira was installed on the throne of the earth as a representative of the Lord. The king is always expected to be the representative of the Lord. Perfect monarchy necessitates representation of the supreme will of the Lord, and Mahārāja Yudhiṣṭhira was the ideal monarch on this supreme principle. Both the King and the subjects were happy in the discharge of worldly duties, and thus protection of the citizens and enjoyment of natural life, with full cooperation of material nature, followed in the reign of Mahārāja Yudhiṣṭhira and his worthy descendants like Mahārāja Parīkṣit.