‘For this reason even the first covenant has not been dedicated without blood. For when every commandment had been spoken by Moses to all the people according to the law, he took the blood of the calves and the goats, with water and scarlet wool and hyssop, and sprinkled both the book itself and all the people, saying, “This is the blood of the covenant which God commanded towards you”.'
Indeed such a death was ever seen as necessary for an important covenant. It sealed it permanently. And it was specifically true of the first covenant. The first idea of the application of blood was that none could withdraw on pain of death. That is why the first covenant, the old covenant, was dedicated with blood and sprinkled on the altar and the people. It bound both parties irrevocably while the conditions were fulfilled. And once the conditions were broken there arose ‘the transgressions which were under the first covenant', and the parties involved in these were, as a result, doomed to die. Thus any new covenant had also necessarily to take into account the need for atonement. Death must be implicit in any new covenant simply because it was required of those who had broken the old.
The making of the old covenant is now described in detail. Once it had been declared, and Moses had described every commandment in the covenant to all the people (for all were to be involved and must know what they were agreeing to), he carried out ceremonial sacrifices in order to seal the covenant with blood, applying the blood both to the record of the covenant itself, and to all the people (Exodus 24:6-8). By this they were bound to obedience to it on pain of death, and God, as the One to Whom the sacrifices were offered, was equally bound to them while they faithfully kept the covenant.
Yet as the context here makes clear, that blood was not just a symbol of the sacredness of the contract, it was also a requirement because of the sinfulness already present on the part of one of the parties involved. Such a contract could not have been made without cleansing for sin. For there was a past to be atoned for, and as we are shortly to be informed, the main purpose of the shedding of blood is the remission of sin (Hebrews 9:22). Furthermore the whole context here is of cleansing from sin (Hebrews 9:12-14; Hebrews 9:21-22). Any explanation therefore that lacks that necessity is itself lacking.
So we may undoubtedly recognise here that the shedding of blood, as well as sealing the covenant, also had a cleansing significance, for whenever blood was shed sacrificially in relation to anything connected with God such a meaning was necessarily involved. Because the contract was made with sinners, cleansing must therefore be involved.
The passage in Exodus does not mention the sprinkling of the blood on the book It does, however, bring the book into close connection with the ceremony. The blood there is sprinkled on the specially erected altar and on the people connecting God with His people. The book may well have been placed on the altar in such ceremonies. The writer may well have been writing on the basis of his knowledge of such ceremonies, or of some tradition which drew this out. Nor does the passage mention the method of sprinkling which is described in the detail given here, which is in fact partly similar to that for the sprinkling of the ashes of the heifer (Numbers 19:6). Note how here it is just assumed that these had been used in the sprinkling. It was thus clearly a recognised custom to use scarlet wool and hyssop for sprinkling, compare Leviticus 14:4; Leviticus 14:6-7.