It is a characteristic technique, often employed by the Teacher in the Geeta, to bring home his ideas, by expressing them, for purposes of emphasis, against the background of their opposites. Thus, we find here in the verse two contradictory factors put in opposition to each other so that, each, as a contrast to the other, may shine out the best in the mental horizon of the students. “UP TO THE REALM OF BRAHMAJI ALL ARE SUBJECT TO REBIRTH.” This idea is contrasted with the result of realising directly and totally the Self, the Eternal: “BUT, AFTER ATTAINING ME THERE IS NO REBIRTH.”
The theory of gradual liberation (Krama Mukti), accepted in Vedanta, says that ritualism (Karma), accompanied by meditation (Upasana), takes the ego to the realm-of-the-Creator (Brahma-loka) where, at the end of the Kalpa (the cycle of creation and dissolution), it merges with the Supreme. Even in Brahma-loka it is necessary that the ego must, through self-effort, live strictly all the spiritual directions of the Creator, and through constant contemplation upon the Self (Atma-Vichara) come to deserve the total liberation, by ending all its connections with “ignorance.” Those who have not reached the realm-of-the-Creator, may not come to enjoy the Supreme-merger. They will, at the end of the Kalpa, have to come back and take their manifestation in embodiments, ordered by their remaining vasanas. This principle is kept in mind when Krishna says that rebirth is for everyone, even to those who have attained any high plane up to Brahma-loka; having once reached Brahma-loka, there is no return, but from there the meditator rises to merge in the Self.
But to those who have awakened to the rediscovery of their essential, Eternal Nature and realised themselves to be the One, All-pervading Self — “AFTER ATTAINING ME” — to them, thereafter, there is no return to the plane of limited-existence. To the waker there is no re-admission into the realm where he was when he was dreaming; to awake is to miss for ever the joys and sorrows of that dream which he had dreamt. After attaining the waker-hood (Me) there is no return (rebirth) into the dreamland (Samsara).