SB 7.8.17
satyam vidhatum nija-bhrtya-bhasitam
vyaptim ca bhutesv akhilesu catmanah
adrsyatatyadbhuta-rupam udvahan
stambhe sabhayam na mrgam na manusam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
To prove that the state ment of His servant Prahlada Maharaja was substantial — in other words, to prove that the Supreme Lord is present everywhere, even within the pillar of an assembly hall — the Supreme Personality of Godhead, Hari, exhibited a wonderful form never before seen. The form was neither that of a man nor that of a lion. Thus the Lord appeared in His wonderful form in the assembly hall.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
When Hiranyakasipu asked Prahlada Maharaja, “Where is your Lord? Is He present in this pillar?” Prahlada Maharaja fearlessly replied, “Yes, my Lord is present everywhere.” Therefore, to convince Hiranyakasipu that the statement of Prahlada Maharaja was unmistakably true, the Lord appeared from the pillar. The Lord appeared as half lion and half man so that Hiranyakasipu could not understand whether the great giant was a lion or a human being. To substantiate Prahlada’s statement, the Lord proved that His devotee, as declared in Bhagavad-gita, is never vanquished (kaunteya pratijanihi na me bhaktah pranasyati). Prahlada Maharaja’s demoniac father had repeatedly threatened to kill Prahlada, but Prahlada was confident that he could not be killed, since he was protected by the Supreme Lord. By appearing from the pillar, the Lord encouraged His devotee, saying in effect, “Don’t worry. I am present here.” By manifesting His form as Nrsimhadeva, the Lord also preserved the truth of Lord Brahma’s promise that Hiranyakasipu was not to be killed by any animal or any man. The Lord appeared in a form that could not be said to be fully a man or a lion.