SB 1.17.12

ko ’vṛścat tava pādāṁs trīn
 saurabheya catuṣ-pada
mā bhūvaṁs tvādṛśā rāṣṭre
 rājñāṁ kṛṣṇānuvartinām
Word for word: 
kaḥ — who is he; avṛścat — cut off; tava — your; pādān — legs; trīn — three; saurabheya — O son of Surabhi; catuḥ-pada — you are four-legged; — never to be; bhūvan — it so happened; tvādṛśāḥ — as yourself; rāṣṭre — in the state; rājñām — of the kings; kṛṣṇa-anuvartinām — those who follow the codes of Kṛṣṇa, the Supreme Personality of Godhead.
Translation: 
He [Mahārāja Parīkṣit] repeatedly addressed and questioned the bull thus: O son of Surabhi, who has cut off your three legs? In the state of the kings who are obedient to the laws of the Supreme Personality of Godhead, Kṛṣṇa, there is no one as unhappy as you.
Purport: 

The kings or the executive heads of all states must know the codes of Lord Kṛṣṇa (generally Bhagavad-gītā and Śrīmad-Bhāgavatam) and must act accordingly in order to fulfill the mission of human life, which is to make an end to all miseries of material conditions. One who knows the codes of Lord Kṛṣṇa can achieve this end without any difficulty. In the Bhagavad-gītā, in a synopsis, we can understand the codes of Godhead, and in the Śrīmad-Bhāgavatam the same codes are explained further.

In a state where the codes of Kṛṣṇa are followed, no one is unhappy. Where such codes are not followed, the first sign is that three legs of the representative of religion are cut off, and thereby all miseries follow. When Kṛṣṇa was personally present, the codes of Kṛṣṇa were being followed without question, but in His absence such codes are presented in the pages of Śrīmad-Bhāgavatam for the guidance of the blind persons who happen to be at the helm of all affairs.