Leviticus 14:4

Then shall the priest command to take. — Literally, And the priest shall command, and he shall take, that is, the leper shall take. To avoid the ambiguity as to the person, the translators of the Authorised Version adopted the rendering in the text. As the relatives of the cured leper procured the things prescribed for the purification, some of the ancient versions render it, And they shall take.

Two birds alive and clean. — These were either sparrows, doves, turtledoves, or any other birds, provided they belonged to the clean species described in Leviticus 11. According to the canons which obtained during the second Temple, the birds had to be sparrows, and the reason assigned for it was that as leprosy was regarded as a Divine punishment for calumny, such birds were selected as were proverbial for their constant twitter. Hence the rendering of sparrow in the Latin Vulgate, and in the Margin of the Authorised Version.

And cedar wood. — This had to be a foot and a half long, and a quarter of the foot of the bed in thickness. Though this wood was primarily chosen for its antiseptic properties, which made it peculiarly suitable for the occasion, still, belonging to the loftiest of trees (Pss. 2:13, Pss. 27:24; Amos 2:9), it also was designed to symbolise the haughtiness of mind which called down the affliction of leprosy.

And scarlet. — This was probably a band of scarlet wool with which the cedar and the hyssop were tied together. In later times the woollen band had to be the weight of a shekel, or weighing thirty-two grains of barley. It was taken to symbolise the purified and now healthy blood.

And hyssop. — This, according to the canons which obtained in the time of Christ, had at least to be a handbreadth in size. It could not be the so-called Greek, or the ornamental, or Roman, or wild hyssop, or any other hyssop which was distinguished by the name of the place where it grew, but had to be the common hyssop which grew in gardens. Though, like the cedar wood, it was primarily used on these occasions for its aromatic properties, yet this diminutive shrub was also most probably designed to symbolise the humility of the cured leper. Hence ancient tradition tells us, “Cedar wood and hyssop, the highest and the lowest, give the leper purity. Why these? Because pride was the cause of the distemper, which cannot be cured till man becomes humble, and keeps himself as low as hyssop.” Cedar wood, hyssop, and scarlet were also burnt with the red heifer (Numbers 19:6), and were generally employed in purifications (Hebrews 9:19). Hence the Psalmist prays, “Purge me with hyssop, and I shall be clean” (Psalms 51:17).