SB 6.17.38
Devanāgarī
जज्ञे त्वष्टुर्दक्षिणाग्नौ दानवीं योनिमाश्रित: । वृत्र इत्यभिविख्यातो ज्ञानविज्ञानसंयुत: ॥ ३८ ॥
Text
jajñe tvaṣṭur dakṣiṇāgnau dānavīṁ yonim āśritaḥ vṛtra ity abhivikhyāto jñāna-vijñāna-saṁyutaḥ
Synonyms
jajñe—was born;tvaṣṭuḥ—of thebrāhmaṇaknown as Tvaṣṭā;dakṣiṇa-agnau—in the fire sacrifice known asdakṣiṇāgni;dānavīm—demoniac;yonim—species of life;āśritaḥ—taking shelter of;vṛtraḥ—Vṛtra;iti—thus;abhivikhyātaḥ—celebrated;jñāna-vijñāna-saṁyutaḥ—fully equipped with transcendental knowledge and practical application of that knowledge in life.
Translation
Being cursed by mother Durgā [Bhavānī, the wife of Lord Śiva], that same Citraketu accepted birth in a demoniac species of life. Although still fully equipped with transcendental knowledge and practical application of that knowledge in life, he appeared as a demon at the fire sacrifice performed by Tvaṣṭā, and thus he became famous as Vṛtrāsura.
Purport
yatra kva vābhadram abhūd amuṣya kiṁ ko vārtha āpto ’bhajatāṁ sva-dharmataḥ
( Bhāg. 1.5.17 )
Once one is advanced in devotional service, his spiritual assets are never lost under any circumstances. Whatever spiritual advancement he has achieved continues. This is confirmed in Bhagavad-gītā. Even if a bhakti-yogī falls, he takes birth in a rich family or family of brāhmaṇas, in which he again starts devotional activities from the point where he left off. Although Vṛtrāsura was known as an asura, or demon, he did not lose his consciousness of Kṛṣṇa or devotional service.