Exodus 4:8-9 ▼

8 “So if they will not believe you nor pay attention to the evidence of the first sign, they may believe the evidence of the last sign.

9 But if they will not believe even these two signs nor pay attention to what you say, then you shall take some water from the Nile and pour it on the dry ground; and the water which you take from the Nile will turn into blood on the dry ground.”