It’s from the time when Moses met GOD at the burning bush. Then I’m his introduction of himself to Moses he revealed himself as the God of the three Patriarchs. Further in the conversation after he revealed his plan of redemption for the Israelites Moses asked again who should he say sent him to them; there he called himself as I AM which the Hebrew translates as Yahweh.
Before Israel had kings they were led by prophets who received instructions from God himself to be given to them. So sort of God was their king until they requested at some point they needed their own king. You know Yahweh, the king of the chosen Israel. The entire purpose of Jesus was to reconcile us back to God who’s not just the father but our king. As we represent the chosen people of GOD through the death and resurrection of Jesus, we are qualified to call God our king and even so he has chosen us to be his royal priesthood.
Yahweh is a song for the saints of God who have been transitioned into the kingdom of His son where he God reigns as king.
Finally let all people declare that he comes. Scripture says the kingdoms of this world has become the kingdom of our lord and His Christ. In the end all nations shall call him lord, when he appears all eye will see him even those who pierced him. Our anthem is not just a chant for churches, but a declaration that Yahweh, the king reigns and reigns forever.