What did it mean to redeem every firstborn son in Exodus 13:13?

 

During the night the Israelites escaped from Egypt, God spared the oldest son of every house marked with blood on the doorframes. Because God saved the lives of the firstborn, he had a rightful claim to them. But God commanded the Israelites to buy their sons back from him. This ritual served three main purposes: (1) it was a reminder to the people of how God had spared their sons from death and freed them all from slavery; (2) it showed Gods high respect for human life in contrast to the pagan gods who, their worshipers believed, demanded human sacrifice; (3) it looked forward to the day when Jesus Christ would buy us back by paying the price for our sin once and for all.