It is said in Hitopadesa, upadeso hi murkhanam prokopaya na santaye. If good instructions are given to a foolish person, he does not take advantage of them, but becomes more and more angry. Prahlada Maharajas authorized instructions to his father were not accepted by Hiranyakasipu as truth; instead Hiranyakasipu became increasingly angry at his great son, who was a pure devotee. This kind of difficulty always exists when a devotee preaches Krsna consciousness to persons like Hiranyakasipu, who are interested in money and women. (The word hiranya means gold, and kasipu 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. Prahlada Maharajas Vaisnava preaching to his demoniac father was indirectly effective, for because of Hiranyakasipus excessive jealousy of Krsna and His devotee, he was inviting Nrsimhadeva to kill him very quickly. Thus he was expediting his being killed by the Lord Himself. Although Hiranyakasipu was a demon, he is described here by the added word sri. Why? The answer is that fortunately he had such a great devotee son as Prahlada Maharaja. Thus although he was a demon, he would attain salvation and return home, back to Godhead.