Exodus 12:22 - Clarke's commentary and critical notes on the Bible

And ye shall take a bunch of hyssop, and dip it in the blood that is in the bason, and strike the lintel and the two side posts with the blood that is in the bason; and none of you shall go out at the door of his house until the morning. A bunch of hyssop - The original word אזוב ezob has been variously translated musk, rosemary, polypody of the wall, mint, origanum, marjoram, and Hyssop: the latter seems to be the most proper. Parkhurst says it is named from its detersive and cleansing qualities, whence it was used in sprinkling the blood of the paschal lamb, in cleansing the leprosy, Leviticus 14:4, Leviticus 14:6, Leviticus 14:51, Leviticus 14:52; in composing the water of purification, Numbers 19:6, and sprinkling it, Numbers 19:18. It was a type of the purifying virtue of the bitter sufferings of Christ. And it is plain, from Psalms 51:7, that the psalmist understood its meaning. Among botanists hyssop is described as "a genus of the gymnospermia (naked-seeded) order, belonging to the didynamia class of plants. It has under-shrubby, low, bushy stalks, growing a foot and a half high, small, spear-shaped, close-sitting, opposite leaves, with several smaller ones rising from the same joint; and all the stalks and branches terminated by erect whorled spikes of flowers of different colors, in the varieties of the plant. The leaves have an aromatic smell, and a warm pungent taste. The leaves of this plant are particularly recommended in humoral asthmas, and other disorders of the breast and lungs, and greatly promote expectoration." Its medicinal qualities were probably the reason why this plant was so particularly recommended in the Scriptures.