Bhagavad Gita · 18.75

व्यासप्रसादाच्छ्रुतवानेतद्गुह्यमहं परम्।योगं योगेश्वरात्कृष्णात्साक्षात्कथयतः स्वयम्॥

vyāsa-prasādāch chhrutavān etad guhyam ahaṁ param yogaṁ yogeśhvarāt kṛiṣhṇāt sākṣhāt kathayataḥ svayam

By the grace of Vyasa, I have heard this supreme secret yoga directly from Krishna, the Lord of Yoga, Himself speaking.

— Bhagavad Gita 18.75

Source: Sacred-Texts.com (Sanskrit) + Bhagavad-Gita.io (translations)