John Calvin on Exodus 32:33

33. Whosoever hath sinned against me, him will I blot out In these words God adapts Himself to the comprehension of the human mind, when He says, “him will I blot out;” for hypocrites make such false profession of His name, that they are not accounted aliens, until God openly renounces them: and hence their manifest rejection is called erasure. Moreover, God reproves the preposterous request of Moses, inasmuch as it does not consist with His justice to reject the innocent; whence it follows, that Moses had prayed inconsiderately. The sum is, that God, whenever He punishes the ungodly and iniquitous, pays them the wages which they have earned; whereas He never punishes the just. Yet it is to be observed, that when God declares that he will be the avenger of sins, His mercy is not excluded, whereby He buries the transgressions of His people, so that they come not into mind. Thus, when Paul says, “Neither fornicators, nor adulterers, nor thieves, nor covetous, nor murderers, nor revilers, shall possess the kingdom of God,” It will be seen that C. here, as is often the case, quotes from memory. (1 Corinthians 6:9, 10;) it would be incorrect to conclude that they were all shut out from the hope of salvation; since he only speaks of the reprobate, who never repent, so that being converted they may obtain grace.