Moses's final argument turned to the deepest court of appeal in the Jewish tradition: the merit of the avot, the patriarchs. Targum Pseudo-Jonathan preserves it precisely: "Remember Abraham, and Izhak, and Israel, Thy servants, to whom Thou didst swear in Thy Word and didst say to them, I will multiply your children as the stars of the heavens, and all this land of which I have told you will I give to your sons, and they shall inherit for ever" (Exodus 32:13).
What is the merit of the patriarchs?
The concept of zechut avot — the merit of the fathers — is one of the most important categories in Jewish theology. The sages taught that the patriarchs had accumulated, through their lives of faithfulness, a reservoir of covenantal credit that their descendants could draw upon in times of crisis. It was not earned by the descendants; it was bequeathed by the ancestors. Abraham's willingness to sacrifice Isaac. Isaac's consent to be bound. Jacob's wrestling through the night. These acts, the tradition held, created a permanent deposit that Israel could call on across the generations.
Moses called on it here. He reminded God of the specific oath — the shevuah — made "in Thy Word," the Memra. The targum's choice of Memra is crucial. The oath was not made lightly, in a passing conversation. It was made in the speaking-self of God, the most binding possible form of divine commitment.
And what was the oath? Two things: children as the stars, and land forever. If Israel were destroyed now, the targum's listener would realize, both halves of the oath would fail. No multiplication. No inheritance. The patriarchs' whole story would collapse.
The sages saw in Moses's final argument the genius of his prayer. First he had invoked God's labor — whom Thou didst bring up. Then God's reputation — the Mizraee will say. Now God's oath — to whom Thou didst swear in Thy Word. Three arguments, each layered on the one before, each binding God more tightly to the covenant God was about to break.
The Maggid takes this home: when you pray for mercy, remember the oaths that were made before you were born. You stand on them even when you cannot see them.