Mbh 12.124.8

"'"'Vrihaspati said, "There is something, O son, that is still higher. The high-souled Bhargava (Usanas) will instruct thee better. Repair to him, blessed be thou, and enquire of him, O chief of the celestials!" Possessed of great ascetic merit and endued with great splendour, the chief of the celestials then repaired to Bhargava and obtained from him with a gratified heart, a knowledge of what was for his great good. Obtaining the permission of the high-souled Bhargava, the performer of a hundred sacrifices once more asked the sage as to whether there was anything higher (as the means for the acquisition of felicity) than what the sage had already told him. The omniscient Bhargava said, "The high-souled Prahlada has better knowledge." Learning this, Indra became highly delighted. The chastiser of Paka, possessed of great intelligence, assumed the form of a Brahmana, and repairing to Prahlada, asked him, saying, "I desire to hear what conduces to felicity." Prahlada answered the Brahmana, saying, "O chief of regenerate ones, I have no time, being wholly occupied in the task of ruling the three worlds, I cannot, therefore, instruct thee." The Brahmana said, "O king, when thou mayst have leisure, I desire to listen to thy instructions about what course of conduct is productive of good." At this answer, king Prahlada became delighted with that utterer of Brahma. Saying, "So be it!" he availed of a favourable opportunity for imparting to the Brahmana the truths of knowledge. The Brahmana duly observed towards Prahlada the conduct which a disciple should observe towards his preceptor, and began with his whole heart to do what Prahlada desired. Many a time the Brahmana enquired, saying, "O chastiser of foes, by what means hast thou been able to win the sovereignty of the three worlds? Tell me, O righteous king, what those means are." Prahlada, O monarch, answered the question the Brahmana asked.