Exodus 4:9

9 If in spite of these two miracles they still will not believe you, and if they refuse to listen to what you say, take some water from the Nile and pour it on the ground. The water will turn into blood."

Exodus 4:9 In-Context

7 Then the Lord said, "Put your hand inside your robe again." He did so, and when he took it out this time, it was healthy, just like the rest of his body.
8 The Lord said, "If they will not believe you or be convinced by the first miracle, then this one will convince them.
9 If in spite of these two miracles they still will not believe you, and if they refuse to listen to what you say, take some water from the Nile and pour it on the ground. The water will turn into blood."
10 But Moses said, "No, Lord, don't send me. I have never been a good speaker, and I haven't become one since you began to speak to me. I am a poor speaker, slow and hesitant."
11 The Lord said to him, "Who gives man his mouth? Who makes him deaf or dumb? Who gives him sight or makes him blind? It is I, the Lord.
Scripture taken from the Good News Translation - Second Edition, Copyright 1992 by American Bible Society. Used by Permission.