Thus it is quite logical that the emphasis on sound is found again at the end of the Vedanta Sutra in its final aphorism: anavrttih sabdad anavrttih sabdat—”Revelation tells us that we never come back. Revelation tells us that we never come back” (4.4.22).
The purport is that when one knows the Lord’s true identity, one attains his abode of Goloka by the influence of his devotional service. Once he is so liberated, he never again returns to this world of repeated birth and death. The proof of this is found in “sound” or revelation (sabda).
The repetition of the phrase anavrittih sabdat is an indication that the Vedanta Sutra ends with these words.