mayabhih sannirodhais ca
na sasaka yada hantum
apapam asurah sutam
cintam dirghatamam praptas
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Hiranyakasipu could not kill his son by throwing him beneath the feet of big elephants, throwing him among huge, fearful snakes, employing destructive spells, hurling him from the top of a hill, conjuring up illusory tricks, administering poison, starving him, exposing him to severe cold, winds, fire and water, or throwing heavy stones to crush him. When Hiranyakasipu found that he could not in any way harm Prahlada, who was completely sinless, he was in great anxiety about what to do next.