Final answer:
God appeared to Abraham, Isaac, and Jacob, but they did not fully understand His nature or His covenant name, Yahweh.
Step-by-step explanation:
In Exodus 6:3, when God says, 'I appeared to Abraham, to Isaac, and to Jacob, as God Almighty, but by my name the Lord I did not make myself known to them,' it means that although God had revealed Himself to these patriarchs, they did not fully understand His nature or His covenant name, Yahweh. The patriarchs primarily knew God as 'El Shaddai' or 'God Almighty.' It was not until Moses and the Israelites were in Egypt that God revealed His covenant name, Yahweh, to Moses at the burning bush.