3,904. How the Incense Was Prepared

Hilchos Klei HaMikdash 2:5

The incense was prepared as follows: Nine kav of lye were brought and the onycha was rubbed with it. The onycha was then soaked in twenty-one kav of Cyprus wine or strong, aged white wine. Next, each spice was individually ground very finely. While grinding, one would say, “Grind well” repeatedly for the duration of the process. All the spices were then mixed together.

Hilchos Klei HaMikdash 2:6

Everything done in preparing the incense was done in sanctity, in the courtyard, using consecrated ingredients. If the incense was made from secular ingredients, it is unfit for use.