Exodus 7:20
18 Fish in the Nile will die, the Nile will stink, and the Egyptians will be unable to drink water from the Nile.”’” 19 Then the Lord said to Moses, “Tell Aaron, ‘Take your staff and stretch out your hand over Egypt’s waters—over their rivers, over their canals, over their ponds, and over all their gathered waters43—so that it becomes blood.’ There will be blood everywhere in the land of Egypt, even in wooden and stone containers.” 20 Moses and Aaron did so, just as the Lord had commanded. He raised the staff and struck the water that was in the Nile right before the eyes of Pharaoh and his servants, and all the water that was in the Nile was turned to blood. 21 When the fish that were in the Nile died, the Nile began to stink, so that the Egyptians could not drink water from the Nile. There was blood everywhere in the land of Egypt! 22 But the magicians of Egypt did the same by their secret arts, and so Pharaoh’s heart remained hard, and he refused to listen to Moses and Aaron—just as the Lord had predicted.
Revelation 8:8
6 Now the seven angels holding the seven trumpets prepared to blow them. 7 The first angel blew his trumpet, and there was hail and fire mixed with blood, and it was thrown at the earth so that a third of the earth was burned up, a third of the trees were burned up, and all the green grass was burned up. 8 Then the second angel blew his trumpet, and something like a great mountain of burning fire was thrown into the sea. A third of the sea became blood, 9 and a third of the creatures living in the sea died, and a third of the ships were completely destroyed. 10 Then the third angel blew his trumpet, and a huge star burning like a torch fell from the sky; it landed on a third of the rivers and on the springs of water.
Notes and References
"... The hardening function of the judgments parallels the effect of God’s judgments on Pharaoh who likewise was hardened and refused to repent (Exodus 7:22–23; 8:15, 19, 32; 9:7, 12, 34–35; 10:20, 27; 11:10; 14:5). This parallel is strengthened by the obvious connection of the trumpet and bowl judgments with the plagues sent against Egypt leading up to the Exodus ... The first trumpet brings hail and fire (Revelation 8:7) and corresponds to Exodus 9:22–25. The second and third trumpets turn water to blood (Revelation 8:8–11) and correspond to Exodus 7:20–25. The fourth trumpet brings darkness (Revelation 8:12) and corresponds to Exodus 10:21–23. The fifth trumpet brings locusts (Revelation 9:1–11) and corresponds to Exodus 10:12–15 ..."
Stewart, Alexander Soteriology as Motivation in the Apocalypse of John (p. 105) Gorgias Press, 2015