SB 7.5.38
sarvair upayair hantavyah
sambhoja-sayanasanaih
suhrl-linga-dharah satrur
muner dustam ivendriyam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Just as uncontrolled senses are the enemies of all yogis engaged in advancing in spiritual life, this Prahlada, who appears to be a friend, is an enemy because I cannot control him. Therefore this enemy, whether eating, sitting or sleeping, must be killed by all means.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Hiranyakasipu planned a campaign to kill Prahlada Maharaja. He would kill his son by administering poison to him while he was eating, by making him sit in boiling oil, or by throwing him under the feet of an elephant while he was lying down. Thus Hiranyakasipu decided to kill his innocent child, who was only five years old, simply because the boy had become a devotee of the Lord. This is the attitude of nondevotees toward devotees.