The 85th prohibition is that we are forbidden from making incense according to the formula used in the ketores, i.e. com­posed of the same mixture of spices in the same measure, with the intention of using it for incense.

The source of this mitzvah is G‑d's statement1 (exalted be He), "[One who makes incense] shall not make it with this formula."

The Torah explains that one who intentionally transgresses this prohibition by making such a mixture with the intention of smelling its smoke receives kares, as it is written,2 "If a person makes it to enjoy its fragrance, he shall be cut off (nichras) from his people." If he did so unintentionally, he must bring a sin offering.

The details of this mitzvah are explained in the beginning of tractate Kerisus.3