Srimad Bhagavatam Canto 04, Chapter 19, Text 26

SB 4.19.26

tad abhijñaya bhagavan
prthuh prthu-parakramah
indraya kupito banam
adattodyata-karmukah
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
 
Maharaja Prthu, who was celebrated as very powerful, immediately took up his bow and arrows and prepared to kill Indra himself, because Indra had introduced such irregular sannyasa orders.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
 
It is the duty of the king not to tolerate the introduction of any irreligious systems. Since King Prthu was an incarnation of the Supreme Personality of Godhead, certainly his duty was to cut down all kinds of irreligious systems. Following in his footsteps, all heads of state should themselves be bona fide representatives of God and should cut down all irreligious systems. Unfortunately they are cowards who declare a secular state. Such a mentality is a way of compromising religious and irreligious systems, but because of this citizens are generally becoming uninterested in spiritual advancement. Thus the situation deteriorates to such an extent that human society becomes hellish.