This thunder is the honey of all beings, and all beings are the honey of this thunder. Likewise this bright, immortal person in this thunder, and that bright, immortal person existing as sound and voice in the body (both are madhu). He indeed is the same as that Self, that Immortal, that Brahman, that All.

In plain words: Thunder and all beings nourish each other like honey. The shining, deathless presence in thunder is the same one that lives in us as our sound and voice. Both are the one Self, Brahman, which is everything.