SB 7.5.7
samyag vidharyatam balo
guru-gehe dvi-jatibhih
visnu-paksaih praticchannair
na bhidyetasya dhir yatha
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Hiranyakasipu advised his assistants: My dear demons, give complete protection to this boy at the gurukula where he is instructed, so that his intelligence will not be further influenced by Vaisnavas who may go there in disguise.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
In our Krsna consciousness movement, the tactic of dressing oneself like an ordinary karmi is necessary because everyone in the demoniac kingdom is against the Vaisnava teachings. Krsna consciousness is not at all to the liking of the demons of the present age. As soon as they see a Vaisnava dressed in saffron garments with beads on his neck and tilaka on his forehead, they are immediately irritated. They criticize the Vaisnavas by sarcastically saying Hare Krsna, and some people also chant Hare Krsna sincerely. In either case, since Hare Krsna is absolute, whether one chants it jokingly or sincerely, it will have its effect. The Vaisnavas are pleased when the demons chant Hare Krsna because this shows that the Hare Krsna movement is taking ground. The greater demons, like Hiranyakasipu, are always prepared to chastise the Vaisnavas, and they try to make arrangements so that Vaisnavas will not come to sell their books and preach Krsna consciousness. Thus what was done by Hiranyakasipu long, long ago is still being done. That is the way of materialistic life. Demons or materialists do not at all like the advancement of Krsna consciousness, and they try to hinder it in many ways. Yet the preachers of Krsna consciousness must go forward — in their Vaisnava dress or any other dress — for the purpose of preaching. Canakya Pandita says that if an honest person deals with a great cheater, it is necessary for him to become a cheater also, not for the purpose of cheating but to make his preaching successful.