What does the setting aside of the firstborn in Exodus 13 indicate?
The setting aside of the firstborn in Exodus 13 indicates a family relationship throughout the tribes of Israel. God instituted it after the Passover deliverance and after the exact 430-year period ended, when Israel moved out of Egypt. It marked Israel as a family before God led them out.
Les explains that in chapter 13 God institutes the setting aside of the firstborn, and this was always indicative of a family relationship throughout the tribes of Israel. This follows the precision of God's timing: the 430 years ended to the exact day as Israel moved out of Egypt after the Passover night. After establishing the firstborn, the account turns to verse 17, where God did not lead them through the way of the Philistines, the shorter route. Instead, they came out of Goshen, traveled down the shore of the Red Sea, and would be led to the deeper part, with mountains nearby, rather than crossing at the high point.