Revelation4:2

This was one long vision, not many separate ones; the angel that said he would show him what is sure to transpire is now starting to do just that. The fact that he says, as he did earlier, that he was in the spirit, is either a confirmation of the same fact, or an indication of going even deeper into a trance-like state; it is not necessary to interpret it to mean that a new vision has begun.

Although “behold” is a command for you to pay attention, its purpose is simply to show amazement. In cases like this one, it is less cumbersome to attach the idea of amazement to the writer than to the reader.

“a throne was being established in heaven,” or as some render it, “a throne was standing in heaven.” The verb used here describes action that was ongoing in the past. The intended meaning of this verb seems to come to light when we look first at the imagery, then turn and look at this verb from the perspective of the meaning of the imagery. A throne is a symbol of authority. We know God has, and always has had, complete authority. So it sounds strange to say that “God’s authority was being established.” Our theology would resist that by reminding us that His authority was from eternity. As I see it, the idea being conveyed is that God’s authority, though already present, was proving itself over and over again in the past to all who were paying attention. Although it has always been established as it pertains to God’s ability to act, it was slowly and progressively being established in the minds of His people as they observed Him in action.