tasya daitya-pateh putras
prahrado ’bhun mahams tesam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Hiranyakasipu had four wonderful, well-qualified sons, of whom the one named Prahlada was the best. Indeed, Prahlada was a reservoir of all transcendental qualities because he was an unalloyed devotee of the Personality of Godhead.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
yasyasti bhaktir bhagavaty akiñcana
sarvair gunais tatra samasate surah
“In one who has unflinching devotional faith in Krsna, all the good qualities of Krsna and the demigods are consistently manifest.” (Bhag. 5.18.12) Prahlada Maharaja is praised herein for having all good qualities because of worshiping the Supreme Personality of Godhead. Therefore, a pure devotee, who has no motives, has all good qualities, material and spiritual. If one is spiritually advanced, being a staunch, liberal devotee of the Lord, all good qualities are manifest in his body. On the other hand, harav abhaktasya kuto mahad-gunah: if one is not a devotee, even if he has some materially good qualities, they have no value. That is the verdict of the Vedas.