"And the Lord said again unto Mosheh, Thus shalt thou speak to the sons of Israel: The God of your fathers, the God of Abraham, the God of Izhak, and the God of Jakob, hath sent me unto you. This is His Name for ever, and this is His Memorial to every generation and generation."
The Targum Pseudo-Jonathan on Exodus (3:15) follows the mystical Name of the previous verse with something more domestic: a family name. "The God of Abraham, the God of Izhak, the God of Jakob." This is the Targum's genius. It sandwiches the cosmic Name between the ancestral one.
Notice the repetition: the God of Abraham, the God of Izhak, the God of Jakob. Why not say "the God of the patriarchs"? The sages of the Mekhilta (tannaitic midrash on Exodus) explained: because each patriarch found God anew, in his own way. Abraham's God was not simply inherited by Isaac. Isaac had to meet Him himself. Jacob had to wrestle Him at the Jabbok. Every generation's relationship with the Holy One is personal — which is why every name gets listed separately.
And then the closing phrase: This is His Memorial to every generation and generation. The Aramaic dukhrana — memorial, remembrance, invocation. This is the Name by which He will be called in the synagogues not yet built, in the exiles not yet suffered, in the generations not yet born.
The theology is staggering. God gives Moses two names in two verses. A cosmic Name that points to His essence (3:14) and a relational Name that points to His history with a particular family (3:15). Moses must hold both. Without the cosmic Name, God is small. Without the family Name, God is distant.
Beloved, the God of your ancestors is the same God who spoke the universe. Both are true at once.