Srimad-Bhagavatam: Canto 11 - Chapter 1 - Verse 15
Sanskrit:
श्रीउद्धव उवाचयदा त्वं सनकादिभ्यो येन रूपेण केशव ।योगमादिष्टवानेतद् रूपमिच्छामि वेदितुम् ॥ १५ ॥
ITRANS:
śrī-uddhava uvācayadā tvaṁ sanakādibhyoyena rūpeṇa keśavayogam ādiṣṭavān etadrūpam icchāmi veditum
Translation:
Śrī Uddhava said: My dear Keśava, at what time and in what form did You instruct the science of yoga to Sanaka and his brothers? I now desire to know about these things.