Here is an interesting comment that Augustine makes on today’s Old Testament reading:
And in case you should suppose that he acted like this more from necessity than from charity, God actually offered him another people: “And I will make you,” he said, “into a great nation,” so leaving himself free to eliminate those others. But Moses wouldn’t accept this: he sticks to the sinners; he prays for the sinners. And how does he pray? This is a wonderful proof of his love, brothers and sisters. How does he pray? Notice something I’ve often spoken of, how his love is almost that of a mother. When God threatened that sacrilegious people, Moses’ maternal instincts were roused, and on their behalf he stood up to the anger of God. “Lord,” he said, “if you will forgive them this sin, forgive; bit if not, blot me out from the book you have written.” What sure maternal and paternal instincts, how sure his reliance, as he said this, on the justice and mercy of God! He knew that because he is just he wouldn’t destroy a just man, and because he is merciful he would pardon sinners.