SB 6.17.39

etat te sarvam ākhyātaṁ
 yan māṁ tvaṁ paripṛcchasi
vṛtrasyāsura-jāteś ca
 kāraṇaṁ bhagavan-mateḥ
Synonyms: 
etat — this; te — unto you; sarvam — all; ākhyātam — explained; yat — which; mām — me; tvam — you; paripṛcchasi — asked; vṛtrasya — of Vṛtrāsura; asura-jāteḥ — whose birth was in a species of asuras; ca — and; kāraṇam — the cause; bhagavat-mateḥ — of exalted intelligence in Kṛṣṇa consciousness.
Translation: 
My dear King Parīkṣit, you inquired from me how Vṛtrāsura, a great devotee, took birth in a demoniac family. Thus I have tried to explain to you everything about this.