Contradiction with Exodus 30:23–25
These verses instruct Moses to make the anointing oil using specific spices and do not mention priests or Levites making it, while 1 Chronicles 9:30 assigns this task to the sons of the priests.
Contradiction with Exodus 30:31–33
This passage states that no one else is to make oil like the sacred anointing oil or to use it for ordinary purposes, whereas 1 Chronicles 9:30 describes the sons of the priests making ointment.