A psalm about earthly rebellion begins in the heavens. YHWH is seated, and he laughs.
Then his answer descends: from the heavens (vv. 4–6), to his king on Zion, the mountain that stands between heaven and earth (vv. 7–9), to the rebel kings below (vv. 10–12). Scriptura’s poetics analysis calls this a deliberate spatial drama: earth → heaven → mountain → earth. YHWH’s answer doesn’t come as a military campaign. It comes as a decree that travels downward through the structure of the universe.
Zion was already the meeting point of heaven and earth. The poem gives that geography a direction.