Srimad-Bhagavatam: Canto 7 - Chapter 1 - Verse 1
श्रीनारद उवाचएवं दैत्यसुतै: पृष्टो महाभागवतोऽसुर: ।उवाच तान्स्मयमान: स्मरन् मदनुभाषितम् ॥ १ ॥
śrī-nārada uvācaevaṁ daitya-sutaiḥ pṛṣṭomahā-bhāgavato ’suraḥuvāca tān smayamānaḥsmaran mad-anubhāṣitam
Nārada Muni said: Although Prahlāda Mahārāja was born in a family of asuras, he was the greatest of all devotees. Having thus been questioned by his class friends, the sons of the asuras, he remembered the words spoken to him by me and replied to his friends as follows.
When he was in the womb of his mother, Prahlāda Mahārāja listened to the words of Nārada Muni. One cannot imagine how the baby in embryo could hear Nārada, but this is spiritual life; progress in spiritual life cannot be obstructed by any material condition. This is called ahaituky apratihatā. Reception of spiritual knowledge is never checked by any material condition. Thus Prahlāda Mahārāja, from his very childhood, spoke spiritual knowledge to his class friends, and certainly it was effective, although all of them were children.