'Behind' in the Bible

I was in the Spirit [in special communication with the Holy Spirit and empowered to receive and record the revelation from Jesus Christ] on the Lord’s Day, and I heard behind me a loud voice like the sound of a trumpet,

and in front of the throne there was something like a sea or large expanse of glass, like [the clearest] crystal. In the center and around the throne were four living creatures who were full of eyes in front and behind [seeing everything and knowing everything that is around them].