On other occasions, the voice of the Father has been heard introducing his Son and commanding people to hearken to the words of the Son (see Matthew 3:17; Matthew 17:5; Joseph Smith History 1:17).
This introduction is unique in that it adds the phrase, “in whom I have glorified my name.” No doubt this has reference to Christ’s fulfillment of the atoning sacrifice that makes immortality and eternal life possible for mankind- which is the “work and glory” of the Father (see Moses 1:39).