TSK · Numbers 19:6

Then he is to take the live bird along with the piece of cedar wood, the scrap of crimson fabric, and the twigs of hyssop, and he is to dip them and the live bird in the blood of the bird slaughtered over the fresh water,

Cleanse me with hyssop and I will be pure; wash me and I will be whiter than snow.

For when Moses had spoken every command to all the people according to the law, he took the blood of calves and goats with water and scarlet wool and hyssop and sprinkled both the book itself and all the people,