|This article may be expanded with text translated from the corresponding article in the Hebrew Wikipedia. (April 2013)|
Origanum syriacum, bible hyssop, Biblical-hyssop, Lebanese oregano or Syrian oregano, is an aromatic perennial herb in the mint family, Lamiaceae. It is a preferred primary ingredient in the spice mixture za'atar, and the plant may also be called za'atar. In Modern Hebrew, it is called ezov, and it may have been the ezov of Classical Hebrew. In many English translations of the Bible, ezov is rendered as hyssop, hence the common name bible hyssop. However, in English, hyssop generally refers to a different plant. Origanum syriacum is native to the Middle East.
In Egypt, Origanum syriacum subsp. sinaicum is a very rare plant grown on stony grounds in Sinai Peninsula including the coastal Mediterranean strip. From the conservation point of view it is an endangered plant. A study of the agronomic and chemical potential of O. syriacum subsp. sinaicum showed that it was superior to O. vulgare subsp. hirtum in herb and oil yields per acre. They also found that the major constituents in the essential oil of O. syriacum subsp. sinaicum was dominated by thymol, gamma-terpinene and p-cymene in a descending manner. 
- "Origanum syriacum". Germplasm Resources Information Network (GRIN) online database. Retrieved 22 April 2013.
- "Origanum syriacum L.". The Plant List. Royal Botanic Gardens, Kew and Missouri Botanical Garden. 2010 onwards. Retrieved 21 April 2013.
- "Origanum syriacum Bible Hyssop". PFAF Plant Database. Plants For A Future. Retrieved 21 April 2013.
- "Origanum syriacum". Missouri Botanical Garden. Retrieved 21 April 2013.
- Khairallah, Simon (1 January 2010). "Plant story - helping to conserve Origanum syriacum". Kew News. Kew Royal Botanic Gardens. Retrieved 21 April 2013.
- Boulos, Loutfy (2002). Flora of Egypt. Volume 3: Verbenaceae-Compositae. Cairo, Egypt: Al-Hadara Publishing. p. 12. ISBN 9775429250.
- Shalaby, A.S.; Elhefnawy, N.; Ghanem, K.; A. EL-Ghareeb, A. (2011). "Agronomic and Chemical Comparison between Origanum vulgare ssp. hirtum and the Cultivated Plants of O. syriacum ssp. sinaicum". Journal of Essential Oil Bearing Plants (M/s Har Krishan Bhalla & Sons) 14 (4). ISSN 0972-060X. Retrieved 21 April 2013.