Verses 11-13 were meant to show the significance of the firstborn, and ultimately to point to Christ.
I wonder how it was decided who had to pay and who didn’t (3:44-51)?! Maybe it went by age?
Why porpoise skin? Do you suppose it is waterproof (4:10)?
Why were the priests only assigned duties from the age of 30 to 50 (4:22-23; 29-30)?
Have you ever felt like David in verses 9-13? Do you turn to God as he does in the following verses?