Charles Ellicott Commentary Exodus 30:37-38

"And the incense which thou shalt make, according to the composition thereof ye shall not make for yourselves: it shall be unto thee holy for Jehovah. Whosoever shall make like unto that, to smell thereof, he shall be cut off from his people." — Exodus 30:37-38 (ASV)

These instructions are similar to those given with respect to the holy oil (Exodus 30:32–33). Neither of the two holy compounds was to be applied to any profane use.