It is said in Hitopadeśa, upadeśo hi mūrkhāṇāṁ prakopāya na śāntaye. If good instructions are given to a foolish person, he does not take advantage of them, but becomes more and more angry. Prahlāda Mahārāja’s authorized instructions to his father were not accepted by Hiraṇyakaśipu as truth; instead Hiraṇyakaśipu became increasingly angry at his great son, who was a pure devotee. This kind of difficulty always exists when a devotee preaches Kṛṣṇa consciousness to persons like Hiraṇyakaśipu, who are interested in money and women. (The word hiraṇya means “gold,” and kaśipu refers to cushions or good bedding.) Moreover, a father does not like to be instructed by his son, especially if the father is a demon. Prahlāda Mahārāja’s Vaiṣṇava preaching to his demoniac father was indirectly effective, for because of Hiraṇyakaśipu’s excessive jealousy of Kṛṣṇa and His devotee, he was inviting Nṛsiṁhadeva to kill him very quickly. Thus he was expediting his being killed by the Lord Himself. Although Hiraṇyakaśipu was a demon, he is described here by the added word śrī. Why? The answer is that fortunately he had such a great devotee son as Prahlāda Mahārāja. Thus although he was a demon, he would attain salvation and return home, back to Godhead.