32:12 Turn from thy fierce wrath - Not as if he thought God were not justly angry, but he begs that he would not be so greatly angry as to consume them. Let mercy rejoice against judgment; repent of this evil - Change the sentence of destruction into that of correction, against thy people which thou broughtest up out of Egypt - For whom thou hast done so great things? Wherefore should the Egyptians say, For mischief did he bring them out - Israel is dear to Moses, as his kindred, as his charge; but it is the glory of God that he is most concerned for. If Israel could perish without any reproach to God's name, Moses could persuade himself to sit down contented; but he cannot bear to hear God reflected on; and therefore this he insists upon, Lord, What will the Egyptians say? They will say, God was either weak, and could not, or fickle, and would not compleat the salvation he begun.
32:7-14 God says to Moses, that the Israelites had corrupted themselves. Sin is the corruption of the sinner, and it is a self-corruption; every man is tempted when he is drawn aside of his own lust. They had turned aside out of the way. Sin is a departing from the way of duty into a by-path. They soon forgot God's works. He sees what they cannot discover, nor is any wickedness of the world hid from him. We could not bear to see the thousandth part of that evil which God sees every day. God expresses the greatness of his just displeasure, after the manner of men who would have prayer of Moses could save them from ruin; thus he was a type of Christ, by whose mediation alone, God would reconcile the world to himself. Moses pleads God's glory. The glorifying God's name, as it ought to be our first petition, and it is so in the Lord's prayer, so it ought to be our great plea. And God's promises are to be our pleas in prayer; for what he has promised he is able to perform. See the power of prayer. In answer to the prayers of Moses, God showed his purpose of sparing the people, as he had before seemed determined on their destruction; which change of the outward discovery of his purpose, is called repenting of the evil.
