SB 7.8.18
sa sattvam enam parito vipasyan
stambhasya madhyad anunirjihanam
nayam mrgo napi naro vicitram
aho kim etan nr-mrgendra-rupam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
While Hiranyakasipu looked all around to find the source of the sound, that wonderful form of the Lord, which could not be ascertained to be either a man or a lion, emerged from the pillar. In amazement, Hiranyakasipu wondered, “What is this creature that is half man and half lion?”
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
A demon cannot calculate the unlimited potency of the Supreme Lord. As stated in the Vedas, parasya saktir vividhaiva sruyate svabhaviki jñana-bala-kriya ca: the different potencies of the Lord are always working as an automatic exhibition of His knowledge. For a demon it is certainly wonderful that the form of a lion and the form of a man can be united, since a demon has no experience of the inconceivable power for which the Supreme Lord is called “all-powerful.” Demons cannot understand the omnipotence of the Lord. They simply compare the Lord to one of them (avajananti mam mudha manusim tanum asritam). Mudhas, rascals, think that Krsna is an ordinary human being who appears for the benefit of other human beings. Param bhavam ajanantah: fools, rascals and demons cannot realize the supreme potency of the Lord, but He can do anything and everything; indeed, He can do whatever He likes. When Hiranyakasipu received benedictions from Lord Brahma, he thought that he was safe, since he received the benediction that he would not be killed either by an animal or by a human being. He never thought that an animal and human being would be combined so that demons like him would be puzzled by such a form. This is the meaning of the Supreme Personality of Godhead’s omnipotence