As I bought a little hyssop plant yesterday, I thought I would investigate this herb more. The name "Hyssop" (Hyssopus officinalis) is of Greek origin. The Hyssopos of Dioscorides was named from azob (a holy herb), because it was used for cleaning sacred places. It is alluded to in the Christian Scriptures: "Purge me with Hyssop, and I shall be clean."
It is a native of Southern Europe and is an evergreen, bushy herb, growing up to about 1/2 metre high, with a square stem, linear leaves and flowers in whorls, six- to 16 flowered. Cultivated for its flower tops, these are often used by being steeped in water to make an infusion, however sometimes it is used as an expectorant. There are three varieties of Hyssop, known respectively by their blue, red and white flowers.
Medicinal uses include it being an expectorant, diaphoretic, stimulant, pectoral, carminative. The healing virtues of hyssop are due to a particular volatile oil, which is stimulative, carminative and sudorific. It admirably promotes expectoration, and in chronic catarrh its diaphoretic and stimulant properties combine to render it of especial value.
The infusion has an agreeable flavour and is used by herbalists in pulmonary diseases.
'Infuse a quarter of an ounce of dried hyssop flowers in a pint of boiling water for ten minutes; sweeten with honey, and take a wineglassful three times a day, for debility of the chest. It is also considered a powerful vermifuge.' (Old Cookery Book)
Hyssop is the most widely used purification and protection herb in magick. Ruled by Juipter and corresponding to the element of Fire, it can be added to baths in sachets, infused and sprinkled on objects or persons to cleanse them, and hung up in the home to purge it of evil and negativity.
Source: A Modern Botanical