Some time ago, being inquisitive to know, Sanat-kumāra, the chief of the boy-saints, accompanied by other great sages, inquired exactly like you about the truths regarding Vāsudeva, the Supreme, from Lord Saṅkarṣaṇa, who is seated at the bottom of the universe.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
आसीनमुर्व्यां भगवन्तमाद्यं सङ्कर्षणं देवमकुण्ठसत्त्वम् । विवित्सवस्तत्त्वमतःपरस्य कुमारमुख्या मुनयोऽन्वपृच्छन्
āsīnamurvyāṃ bhagavantamādyaṃ saṅkarṣaṇaṃ devamakuṇṭhasattvam | vivitsavastattvamataḥparasya kumāramukhyā munayo'nvapṛcchan
SB 3.8.3