G-d tells Moses to instruct the Israelites on the mitzvah of redeeming the first-born. Instead of doing so, Moses tells them to always remember the enslavement in Egypt and the Exodus, and only thereafter dictates the mitzvah of redeeming the first-born (Exodus13:1-15).
The Jerusalem Talmud says that the amount specified to redeem the first-born (five shekels) is equivalent to the sum for which the brothers sold Joseph into slavery.
As important as treatment of a disease is, prevention of disease is even more important. We are instructed to redeem the first-born to commemorate the miracle when G-d smote the Egyptian first-born, the rock-bottom phenomenon that brought Pharaoh to his knees.
When G-d told Moses to dictate the mitzvah of redeeming the first-born, with the five shekels representing the sale of Joseph, Moses prefaced this with the episode of exodus. How did the Jews end up in Egypt in the first place? Because of the envy of the brothers that led them to the heinous deed of selling their brother into slavery.
Gross character defects can lead to cruel behavior and disastrous consequences.