Genesis 9:5
3 You may eat any moving thing that lives. As I gave you the green plants, I now give you everything. 4 “But you must not eat meat with its life (that is, its blood) in it. 5 For your lifeblood I will surely exact punishment, from every living creature I will exact punishment. From each person I will exact punishment for the life of the individual since the man was his relative. 6 “Whoever sheds human blood, by other humans must his blood be shed; for in God’s image God has made humankind. 7 “But as for you, be fruitful and multiply; increase abundantly on the earth and multiply on it.”
1 Enoch 47:4
3 In those days, I saw the Head of Days when He seated himself upon the throne of His glory, and the books of the living were opened before Him; and all His host which is in heaven above and His counselors stood before Him. 4 And the hearts of the holy were filled with joy because the number of the righteous had been offered, the prayer of the righteous had been heard, and the blood of the righteous had been required before the Lord of Spirits.
Notes and References
"... Revelation 6:10 reads like a dramatization of the rhetorical questions attributed to Jesus in Luke 18:7: “Will not God vindicate his elect who cry to him day and night? Will he long delay over them?” ... The verb ἐκδικεῖν, “to avenge,” occurs only here and in 19:2, where the vengeance prayed for is clearly fulfilled. In the Old Testament, the shedding of human blood is a crime that requires compensation, often the death of the murderer (Genesis 9:5–6; Numbers 35:33; compare the formula “his blood is on his head” in Joshua 2:19; 2 Samuel 1:16; 1 Kings 2:33, 37; Ezekiel 33:4; Matthew 27:25) ... The prayer for vengeance by the martyrs in Revelation 6:10 also has a close parallel in 1 Enoch 47:4 and 4 Ezra 4:35–37, texts composed during the late first century A.D. A partial parallel is found in 1 Enoch 8:4–11:2 (a continuation of 7:1–6, since 8:1–3 is probably an interpolation; see Black, 1 Enoch 128) The destruction of humanity by the giants motivates the survivors to cry to heaven for help (8:4). The four archangels convey their prayer to God (9:1–11) ..."
Aune, David Word Biblical Commentary: Revelation 6-16 (pp. 191-192) Zondervan, 2017