“He who sits in the heavens laughs.
Yahweh has them in derision.
Then he will speak to them in his wrath.
He will terrify them in his fury.
‘I have set my king on Zion,
My holy hill.’”
Yahweh is really the king in heaven. There he sits and looks at distain on the earth. However, when he speaks, he speaks in anger and tries to terrify the various nations. He has set his king on the his holy hill of Mount Zion, the southern highest hill in Jerusalem. There can be no doubt that Yahweh is the king and his favorite mountain is in Jerusalem where David setup his kingdom. The king on Zion is of course David.