Sforno on Exodus 32:34/ספורנו על שמות ל״ב:ל״ד

1אל אשר דברתי לך, when I said to you “I will take you out from the afflictions in Egypt (Exodus 3,17) to a good land etc.”,(verse 8 same chapter).

2וביום פקדי, in the event that they will commit further sins, (such as the sin of the spies)

3ופקדתי עליהם חטאתם, this sin, and I will not continue to waive their punishment for this sin. We find a similar statement in Kings I 1,52 ואם רעה תמצא בו ומת, “if he commits any further evil he will die.” (Adoniah, Solomon’s older brother and former rival for the succession) We find that G’d comes back to this threat in Numbers 14,11 complaining “how long will this people spurn Me, etc.” Seeing that they repeated their rebellious behaviour one could only expect that they would persist in their foolish ways. Our sages used this to coin the phrase that “when a person has sinned, gotten away with it, and sinned again, and again gotten away with it, he thinks that what he did is not even sinful” (so that he has no incentive to repent what he has come to believe is permissible conduct) (Yuma 86)