What is the significance of the bull having no blemish?
Leviticus (Lévitique) 4:3 (ESV)
3if it is the anointed priest who sins, thus bringing guilt on the people, then he shall offer for the sin that he has committed a bull from the herd without blemish to the LORD for a sin offering.
An animal without defect was one that was prized. It was a real sacrifice to present these animals to the slaughter. See commentary on Leviticus 1:3.
3 if it is the anointed priest who sins, thus bringing guilt on the people, then he shall offer for the sin that he has committed a bull from the herd without blemish to the LORD for a sin offering.