4.3 सः that, एव even, अयम् this, मया by Me, ते to thee, अद्य today, योगः Yoga, प्रोक्तः has been taught, पुरातनः ancient, भक्तः devotee, असि thou art, मे My, सखा friend, च and, इति thus, रहस्यम् secret, हि for, एतत् this, उत्तमम् best.Commentary: This Yoga contains profound and subtle teachings. Hence it is the supreme secret which is revealed by the Lord.