Listen to what I have to say. 2 I will open my mouth in parables, I will speak out hidden things, things from ancient times - "

 I will talk in a way that will be hard for a child to understand.

The parable is intentionally hidden in the sacred text God blesses the covenant people and curses the wicked new creation. 

This Psalm says that God is one who reigns over all things.  The saint is happy because the declaration is still flowing, the declaration is a letter from God.  God does not get offerings from the independent nation. But he controls the authority of the eternal kingdom.

This is the additional purpose of the Psalms. God decided before the world was created that he would give people blessings and curses.

76 1" O my people, hear my teaching listen to the words of my mouth. 2 I will open my mouth in parables, I will utter hidden things, things from of old--" The Psalmist is convincingly demonstrating Gods Law, covenants, curses decrees, comprehensive statutes and promise are authoritative pronouncements in the specific context of blessing and cursing. The parable is intentionally hidden in the sacred text. God blesses the covenant people and curses the wicked. The operative word of the authoritative pronouncements is passed on in describing the new creation. This Psalm is streaming the authoritative pronouncements. The cheerful disposition of the considered saint who is always streaming the pronouncement. God does not command offers to the independent nation. But operationally command the authoritative pronouncements of the eternal kingdom. This is the ulterior purpose of the Psalms. We recognize in the history of Israel the prophetic God who descends from His eternal counsel determined before the foundation of the world to speak blessing and curses.