Cleanse me with hyssop, and I will be clean; wash me and I will be whiter than snow.
Psalms 51:7 (NIV)
There were many things that could make a person unclean in the Old Testament period. A person could be spiritually unclean as a result of disobedience to God, as David was acknowledging in this psalm that he wrote after his adulterous act with Bathsheba. However, there are also the more practical applications for physical cleansing. Proper cleansing was so important that emphasis was placed on it by performing a prescribed ceremony or ritual in certain circumstances.
The priest shall order that two live clean birds and some cedar wood, scarlet yarn and the hyssop be brought for the one to be cleansed.
Leviticus 14: 4 (NIV)
This verse describes the elements required to perform the ceremonial cleansing of a person who has been healed of an infectious skin disease. The hyssop was to be dipped, together with the other ingredients, into the blood of one of the birds which was then sprinkled over the person seven times. The same procedure is followed to ceremonially cleanse a house that has been cleared of mildew (Lev 14:51). Again in Numbers chapter 19 we see the same ingredients (hyssop, cedar and scarlet yarn) thrown onto a burning red heifer, the ashes of which are used in the water of cleansing. This water of cleansing is then used to purify a person who has touched a dead body, a human bone or a grave. This may have been because of the anti-fungal  and anti-microbial  properties of hyssop. A sprinkler was made from a bunch of hyssop branches that had been attached to a rod of cedar wood. The sprinkler is dipped into the cleansing water and the water is sprinkled on the unclean person on the third and seventh day, as well as the tent in which the death occurred and all the furnishings that are inside it. Hyssop was also used on the first Passover, as can be seen in Exodus 12:22 (NIV):
Take a bunch of hyssop, dip it into the blood in the basin and put some of the blood on the top and on both sides of the doorframe…
The hyssop commonly known today is Hyssop officinalis and is also an aromatic herb. However, this does not grow in the area that it would need to be sourced from and so could not be the same hyssop mentioned in the bible. The hyssop used in the bible is a member of the mint family, Majorana syriaca also known as Origanum syriacum , which is called Syrian oregano or bible hyssop  and grows to about 1 meter high. The green leaves turn grey after flowering and the branches become woody and hairy; and so hold water very well – making it particularly useful for sprinkling the cleansing water or blood for cleansing ceremonies. This plant grows in Israel in rocky soil and has a straight stalk and white flowers. There is support for this classification in 1 Kings 4:33 where the extent of the Wisdom of Solomon is being explained; including his knowledge of the natural world and his classification of plants and animals:
He described plant life, from the cedar of Lebanon to the hyssop that grows out of walls…
Used in conjunction with the hyssop was the cedar wood. Unless it was specifically stated that it was the Cedar of Lebanon, Cedrus libani , any reference to cedar is considered to be a different species of tree. The cleansing element of Leviticus and Numbers is generally accepted to be a species of pine or juniper. In this instance it is most likely Juniperus oxycedrus  or Juniperus phoenicea , although there is no consensus among the experts.
- R. A. Daouk, S. M. Dagher and E. J. Sattout, “Antifungal Activity of the Essential Oil of Origanum syriacum L.,” Journal of Food Protection, vol. 58, no. 10, pp. 1147-1149, 1995.
- M. H. Alma, A. Mavi, M. Digrak and T. Hirata, “Screening Chemical Composition and in Vitro Antioxidant and Antimicrobial Activities of the Essential Oils from Origanum syriacum L. Growing in Turkey,” Biological and Pharmaceutical Bulletin, vol. 26, no. 12, pp. 1725-1729, 2003.
- Z. Wlodarczyk, “Review of Plant Species Cited in the Bible,” Folia Horticulturae, vol. 19, no. 1, pp. 67-85, 2007.
- Gordon-Conwell Theological Seminary, “Cultural and Historical Notes: Hyssop and the Rituals of Cleansing,” in Archaeological Study Bible, Michigan, Zondervan, 2005, p. 847.
- M. C. Tenney, The Zondervan Pictorial Bible Dictionary, Michigan: Zondervan Publishing House, 1974.