Or HaChaim on Exodus 30:37/אור החיים על שמות ל׳:ל״ז

1 והקטרת אשר תעשה, "And the incense which you are to make, etc." According to Keritut 6 the words: "you shall make," mean that Moses was to separate an amount needed for the daily incense offerings from the total on the day it would be used. This means that if an individual would compound an amount of incense of even half the daily portion offered on the altar, [the daily portion was divided into a half to be offered in the morning and the other half to be offered close to evening. Ed.] such an individual would be guilty of the most severe karet penalty; he would be cut off from his people (for all times).

2לא תעשו, "you must not make it, etc." This means that even if the person making it had no intention of smelling the incense he had made he would still be guilty of a penalty though not the same penalty as if he had smelled the fragrance of the incense he had compounded. We derive this conclusion from the fact that the Karet penalty is mentioned in our portion only in verse 38 where the Torah speaks of someone smelling the incense.