For when Moses had spoken every precept to all the people according to the law, he took the blood of calves and of goats, with water, and scarlet wool, and hyssop, and sprinkled both the book, and all the people,
For - Confirming Hebrews 9:18.
Spoken every precept ... according to the law - adhering to every ordinance (Ephesians 2:15). Compare "Moses told all the words of the Lord, and all the judgments; and all the people answered," etc.
The blood of calves, х ton (G3588)] - 'the calves,' those sacrificed by the "young men" sent by Moses to do so (Exodus 24:3; Exodus 24:5). The "peace offerings" were "of oxen" (Septuagint [moscharia], 'little calves'), and the "burnt offerings" were probably (though this is not specified), as on the day of atonement, goats. The law of Exodus sanctioned formally many sacrificial practices handed down from the primitive revelation.
With water - prescribed not in Exodus 24:1-18, but in other purifications, as ex. gr., of the leper, and the water of separation, which contained the ashes of the red heifer.
Scarlet wool, and hyssop - ordinarily used for purification. Scarlet or crimson, resembling blood: thought to be a peculiarly deep dye, whence it typified sin (note, Isaiah 1:18). So Jesus wore a scarlet robe, emblem of the deep-dyed sins He bore on Him, though He had none in Him. Wool was used as retaining water; the hyssop, as a tufty plant (wrapped round with the scarlet wool) for sprinkling it. The wool was also a symbol of purity. The hyssopus officinalis grows on walls, with small lancet-formed wooly leaves an inch long, with blue and white flowers, and a knotty stalk about a foot high.
Sprinkled ... the book - out of which he read "every precept:" not mentioned in Exodus 24:7. Hence, Bengel, 'And (having taken) the book itself (so Exodus 24:7), he both sprinkled all the people, and (Hebrews 9:21) moreover х kai (G2532) de (G1161)] sprinkled the tabernacle.' The 'itself' expressing that the testament was more important than that blood. The double exhibition, of the blood and of the book, thus constituted the 'dedication' (Hebrews 9:18). But the "and" х kai (G2532)] before "sprinkled" is thus superfluous; whereas in the English version it regularly follows х te (G5037)] "both." Paul, by inspiration, supplies the particular specified here. The sprinkling of the roll х biblion (G975)] of the testament, as well as the people, implies that neither can the law be fulfilled nor the people purged from sins, except by the sprinkling of Christ's blood (1 Peter 1:2). Compare Hebrews 9:23, which shows that there is something antitypical to the Bible in heaven (cf. Revelation 20:12). 'Itself' distinguishes the book from the 'precepts' in it which he 'spake.'