In Ezekiel 40:42, they signify as follows: height, degrees of good and truth from the Highest or Inmost to the lowest or outermost; length, good; breadth, truth. (Apocalypse Explained 627[4])

In Revelation 21:16, they signify that all things of the New Jerusalem are from the good of love and equal; length signifies the good of love; breadth, truth from that love, and height, good and truth together in every degree. (Apocalypse Revealed 907)

In the physical world, the places we inhabit and the distances between them are physical realities, and we have to get our physical bodies through the physical space between to get from one physical place to another physical place. In the spiritual world, however, the "places" we inhabit and the “distances” between them are spiritual realities, which means they are reflections of our thoughts and affections. "Going" from one place to another, then, is a change in spiritual state -- exploring different thoughts and embracing different feelings. Since the Bible is a spiritual book, "going" there also indicates a change or progression in spiritual state, from one mode of thinking and feeling to another mode of thinking and feeling. Obviously, this makes the precise meaning of "go" in the Bible highly dependent on context: Who is going? Where are they going? Why are they going there? Are they following someone or something? Those questions are crucial to the precise meaning. Used on its own, though, "going" represents the normal progression of life, moving through spiritual states as the Lord intends. This has its roots in early Biblical times, when people were nomadic and moved from place to place in a regular progression of life.