Numbers 19:6

Cedar wood, and hyssop, and scarlet. These very items were used in the cleansing of the leper (Lev. 14:4, 6, 49, 51). Cast upon the still-burning heifer, they were thus mixed with the ashes of the carcass to form ingredients of cleansing. Both cedar and hyssop were credited by the ancients with various medicinal properties. The scarlet thread matched the color of the heifer. Cedar wood was regarded as an emblem of fragrance and incorruption, the hyssop as a symbol of purification. Scarlet was a symbol of sin (Isa. 1:18). In all three there was a typical reference to the shedding of the blood of Christ (see Heb. 9:13, 14).