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.