John Gill Commentary 1 Chronicles 9:30

"And some of the sons of the priests prepared the confection of the spices." — 1 Chronicles 9:30 (ASV)

And some of the sons of the priests made the ointment of the
spices .
] For though the Levites had the care of the spices, they might not make the ointment with them, only the priests, see (Exodus 30:23) .