Hebrews 11:4

By faith Abel offered to God more sacrifice than Cain; on account of which he received testimony that he was righteous, God testifying of his gifts; and by it he, though dead, yet speaks.

Hebrews 9:22

And, indeed, according to the law, almost all things are cleansed by blood; and without the shedding of blood there is no remission.

1 Peter 1:19-20

but with the precious blood of Christ, as of a lamb without spot and blemish,

Revelation 13:8

And all that dwell upon the earth will worship him, those whose names are not written in the book of life of the Lamb that was slain from the foundation of the world.

Treasury of Scripture Knowledge

Summary

And Abel, he also brought of the firstlings of his flock and of the fat thereof. And the LORD had respect unto Abel and to his offering:

Bible References

The firstlings

Hebrews 9:22
And, indeed, according to the law, almost all things are cleansed by blood; and without the shedding of blood there is no remission.
1 Peter 1:19
but with the precious blood of Christ, as of a lamb without spot and blemish,
Revelation 13:8
And all that dwell upon the earth will worship him, those whose names are not written in the book of life of the Lamb that was slain from the foundation of the world.