Numbers 19:6 - Ellicott's Commentary On The Whole Bible

And the priest shall take cedar wood, and hyssop, and scarlet. — According to the Targum of Jonathan, another priest was to do this, but the reference seems to be to Eleazar. Cedar-wood may be regarded as the emblem of fragrance and incorruption; hyssop as the emblem of purification; and scarlet (or crimson) wool or cloth may be regarded as emblematical both of sin, which is compared to it in Isaiah 1:18, and also of the blood, which is the life, the shedding of which was needful in order to the remission of sin. All of these were used in the purification of the leper (Leviticus 14:4). In both cases there appears to be a typical reference to the sprinkling of the blood of Christ. (See. Hebrews 9:13-14).