Moses stood before Israel and said: "You have been shown to know that the Lord, He is God; there is none beside Him" (Deuteronomy 4:35). Not told — shown. The plagues, the sea, the fire at Sinai, the manna in the wilderness — Israel was shown, not just instructed. The demonstration was the theology.
Before God chose Israel, the midrash says, no one in the world knew that He was the God of the world. "Pour out Your wrath on the nations that do not know You" (Jeremiah 10:25) — the nations did not know because they had not been shown. They had their own gods, their own cosmologies, their own explanations for the world's order. Then the Exodus happened, and the nations who had watched from the outside — including those who fought against Israel — had to account for what they had seen.
The psalm places Judah at the center of this revelation: "God is known in Judah; His name is great in Israel" (Psalm 76:2). The knowledge spreads outward from the specific to the general: first Judah, then Israel, then the nations. The revelation is not democratic — it begins with the particular covenant people and moves outward. Moses showed Israel first. The nations learned by watching what happened to the people God had chosen to show.