" The doxology moves then to assert that Israel is forever and Yahweh's commitment to Israel is also forever. We had better approach any such doxology suspiciously.
The word "forever" is a clue word, because when it occurs we are likely dealing with state truth.23 That point would perhaps not be noticeable if Yahweh were forever. But it is the people Israel who are said to be "forever." By such a rhetorical move, the main jeopardy from the dreaded God has been removed for the dynasty. Yahweh has now been claimed as a friendly and reliable patron for the regime.
When doxology is used in the context of state truth, it has a political function. Ostensibly it enhances God, but when used as it is used here, it has a political function. Praise of God is by necessary implication praise of and legitimization of the regime. So the "foreverness" is processed as a dynastic claim. The "

― Walter Brueggemann , David's Truth