स एवायं मया तेऽद्य योगः प्रोक्तः पुरातनः।
भक्तोऽसि मे सखा चेति रहस्यं ह्येतदुत्तमम्।।4.3।।
4.3 That ancient Yoga itself, which is this, has been taught to you by Me today, considering that you are My devotee and friend, For, this (Yoga) is a profound secret.
4.3 It is the same ancient, unchanged Yoga which is now taught to you, who out of friendship and overwhelming devotion have resorted to Me whole-heartedly. The meaning is that it has been taught to you fully with all its accessories. Because it is the most mysterious knowledge declared in the Vedanta, it cannot be known or taught by anyone other than Myself. In this connection, in order to know the truth about the Lords descent correctly, Arjuna asked:
Sa evaayam mayaa te’dya yogah proktah puraatanah; Bhakto’si me sakhaa cheti rahasyam hyetad uttamam.
saḥ—that; eva—certainly; ayam—this; mayā—by me; te—unto you; adya—today; yogaḥ—the science of Yog; proktaḥ—reveal; purātanaḥ—ancient; bhaktaḥ—devotee; asi—you are; me—my; sakhā—friend; cha—and; iti—therefore; rahasyam—secret; hi—certainly; etat—this; uttamam—supreme