Summary: Abel's blood cried out for vengeance, but Jesus' blood goes on speaking gracious words of mercy.
THE BLOOD OF SPRINKLING
The first mention of the sprinkling of blood is found in the institution of the Passover (Exodus 12:7). The writer to the Hebrews explains the significance of this: it is ‘lest he that destroyed the firstborn might touch them’ (Hebrews 11:28). The sprinkling of blood was supposed to be repeated every Passover (cf. 2 Chronicles 35:11).
Later, as an affirmation of the covenant, Moses sprinkled blood on both the Book and the people, and both the tabernacle and even the vessels of the ministry (Exodus 24:7-8; Hebrews 9:19-21). Blood was also sprinkled before the LORD in front of the veil of the sanctuary as part of the sin offering (Leviticus 4:6). Blood was also sprinkled directly in front of the tabernacle of meeting at the time of purification of the water of separation (Numbers 19:4).
However, the ultimate “blood of sprinkling” (Hebrews 12:24) is the ‘sprinkling of the blood of Jesus Christ’ (cf. 1 Peter 1:2). We see here that this is a blood that “speaks”; and that it “speaks better things than that of Abel” (Hebrews 12:24).
When Adam and Eve first ate of the forbidden fruit, they tried to cover their loss of the Glory by sewing fig leaves together to make themselves some kind of covering (Genesis 3:7). However, this was not adequate: but God in His mercy and in His grace made them garments of skin and clothed them (Genesis 3:21). This was the institution of the sacrificial system, and ever since then ‘without the shedding of blood there is no remission of sins’ (Hebrews 9:22).
This forms the background for the history of Cain and Abel. Cain was a farmer and brought of the produce of the land: but that on its own was not enough (Genesis 4:3-5). Perhaps the difference between Cain and those who later made the bloodless ‘grain offering’ (Leviticus 2:1-16) was that they were already covered by the blood.
Now Abel was counted righteous before the LORD (Hebrews 11:4), but he was the innocent victim of the first ever murder (Genesis 4:8). Abel’s blood cried out to the LORD from the ground (Genesis 4:10). It, like the law - represented here as Mount Sinai (Hebrews 12:18-21) - cried out for vengeance.
Mount Zion is described as “the city of the living God, the heavenly Jerusalem” (Hebrews 12:22). This has been celebrated in Psalms and songs of long ago (Psalm 48:1-2). Here are gathered not only the “angels” (Hebrews 12:22), but also “the church of the first-born ones, registered in heaven” (Hebrews 12:23).
The “first-born” include not only those who have gone before, but also all who believe (Hebrews 11:40), and all who will ever yet obtain ‘like precious faith’ (2 Peter 1:1). This constitutes ‘a number which no man could number, out of every tribe and tongue and people and nation’ (Revelation 7:9). Here also “ye are come” (Hebrews 12:22).
Those who come are “just” (Hebrews 12:23). We are made “perfect” (Hebrews 12:23) through the “sprinkling” (Hebrews 12:24) of the blood of our Lord Jesus Christ. We are ‘justified by faith’ (Romans 5:1) - made righteous by faith in the Lord Jesus Christ (Romans 3:21-22).
Therefore, we are bold to approach the throne of God (Hebrews 4:16). We come ‘looking unto Jesus’ (Hebrews 12:2) and bearing in mind what He has done for us (Hebrews 12:3). We come to “the Judge of all” (Hebrews 12:23), knowing that ‘the Judge of all the earth’ shall do right (Genesis 18:25).
We come to Jesus, the mediator of the new covenant. We come to His blood sprinkled upon the altar (Hebrews 12:24). Abel’s blood cried out for vengeance (Genesis 4:10) - but Jesus’ blood goes on speaking gracious words of mercy (1 John 1:9; 1 John 2:1-2).