The first plague, according to the Book of Exodus, was water turning to blood.
Based on the reference provided about the Ten Plagues of Egypt, the order of the plagues is as follows:
| Order | Plague |
|---|---|
| 1 | Water turning to blood |
| 2 | Frogs |
| 3 | Lice |
Therefore, the plague of water turning to blood came first.
