Negative commandment · Lo Ta’aseh #85 of 613
Not to duplicate the composition of the incense offering
שלא לעשות במתכונת הקטורת
The verse · Shemot 30:37
וְהַקְּטֹרֶת אֲשֶׁר תַּעֲשֶׂה בְּמַתְכֻּנְתָּהּ לֹא תַעֲשׂוּ לָכֶם קֹדֶשׁ תִּהְיֶה לְךָ לַה׳
“And as for the perfume which thou shalt make, you shall not make it for yourselves according to its prescribed composition: it shall be holy for the Lord.”
The Rambam’s words
Not to duplicate the composition of the incense offering, as [Exodus 30:37] states: "Do not duplicate its formula."
שלא לעשות במתכונת הקטורת, שנאמר "ובמתכונתה, לא תעשו" (ראה שמות ל,לז).
Why · Sefer HaChinuch #110
To not make incense according to the specification of the incense
“It is from the roots of this commandment also [that it is] for the aggrandizement of the [Temple] and everything that is in it. And therefore, it is not fit for commoners to use this precious oil in the [Temple], only the chosen ones of the people alone — and they are the priests and the kings.”
Who & when
“And this commandment of the prohibition of making it is practiced in every place and at all times by males and females.”
Where in the Mishneh Torah
Hilchot Vessels of the Sanctuary and Those Who Serve Therein הלכות כלי המקדש והעובדין בו