Bhagavad Gita 4.3

स अवायं माया तेऽद्य योग: प्रोक्त: पुरातन: |
भक्तोऽसि मे सखा चेति रहस्यं ह्येतदुत्तमम्

Translation

The same ancient knowledge of Yog, which is the supreme secret, I am today revealing unto you, because you are My friend as well as My devotee, who can understand this transcendental wisdom.